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  • richardmitnick 12:17 pm on January 29, 2023 Permalink | Reply
    Tags: "A leap in preserving the quantum coherence of quantum dot spin qubits as part of the global push for practical quantum networks and quantum computers.", A simple material's solution to this problem that improves the storage of quantum information beyond hundred microseconds., , Converting stationary quantum information (such as the quantum state of an ion or a solid-state spin qubit) into light, Enabling the creation of entangled light states for all-photonic quantum computing and allowing foundational quantum control experiments of the nuclear spin ensemble., Optically active semiconductor quantum dots are the most efficient spin-photon interface known to date but extending their storage time beyond a few microseconds has puzzled physicists., Quantum Computing, Quantum Dots are crystalline structures made out of many thousands of atoms., Quantum dots can now combine high photonic quantum efficiency with long spin coherence times., Spin-photon interfaces are elementary building blocks for quantum networks., The Cavendish Laboratory - Department of Physics,   

    From The Cavendish Laboratory – Department of Physics At The University of Cambridge (UK): “Researchers find ways to improve the storage time of quantum information in a spin rich material” 

    From The Cavendish Laboratory – Department of Physics


    U Cambridge bloc

    The University of Cambridge (UK)


    Submitted by Pooja Pandey

    An international team of scientists have demonstrated a leap in preserving the quantum coherence of quantum dot spin qubits as part of the global push for practical quantum networks and quantum computers.

    These technologies will be transformative to a broad range of industries and research efforts: from the security of information transfer, through the search for materials and chemicals with novel properties, to measurements of fundamental physical phenomena requiring precise time synchronization among the sensors.

    Spin-photon interfaces are elementary building blocks for quantum networks that allow converting stationary quantum information (such as the quantum state of an ion or a solid-state spin qubit) into light, namely photons, that can be distributed over large distances. A major challenge is to find an interface that is both good at storing quantum information and efficient at converting it into light. Optically active semiconductor quantum dots are the most efficient spin-photon interface known to date but extending their storage time beyond a few microseconds has puzzled physicists in spite of decade-long research efforts. Now, researchers at the University of Cambridge, the University of Linz and the University of Sheffield have shown that there is a simple material’s solution to this problem that improves the storage of quantum information beyond hundred microseconds.

    Quantum Dots are crystalline structures made out of many thousands of atoms. Each of these atoms’ nuclei has a magnetic dipole moment that couples to the quantum dot electron and can cause the loss of quantum information stored in the electron qubit. The research team’s finding, reported in Nature Nanotechnology [below], is that in a device constructed with semiconductor materials that have the same lattice parameter, the nuclei ‘felt’ the same environment and behaved in unison. As a result, it is now possible to filter out this nuclear noise and achieve a near two-order magnitude improvement in storage time.

    “This is a completely new regime for optically active quantum dots where we can switch off the interaction with nuclei and refocus the electron spin over and over again to keep its quantum state alive,” said Claire Le Gall from Cambridge’s Cavendish Laboratory, who led the project. “We demonstrated hundreds of microseconds in our work, but really, now we are in this regime, we know that much longer coherence times are within reach. For spins in quantum dots, short coherence times were the biggest roadblock to applications, and this finding offers a clear and simple solution to that.”

    While exploring the hundred-microsecond timescales for the first time, the researchers were pleasantly surprised to find that the electron only sees noise from the nuclei as opposed to, say, electrical noise in the device. This is really a great position to be in because the nuclear ensemble is an isolated quantum system, and the coherent electron will be a gateway to quantum phenomena in large nuclear spin ensemble.

    Another thing that surprised the researchers was the ‘sound’ that was picked up from the nuclei. It was not quite as harmonious as was initially anticipated, and there is room for further improvement in the system’s quantum coherence through further material engineering.

    “When we started working with the lattice-matched material system employed in this work, getting quantum dots with well-defined properties and good optical quality wasn’t easy” – says Armando Rastelli, co-author of this paper at the University of Linz. “It is very rewarding to see that an initially curiosity-driven research line on a rather ´exotic´ system and the perseverance of skilled team members Santanu Manna and Saimon Covre da Silva led to the devices at the basis of these spectacular results. Now we know what our nanostructures are good for, and we are thrilled by the perspective of further engineering their properties together with our collaborators.”

    “One of the most exciting things about this research is taming a complex quantum system: a hundred thousand nuclei coupling strongly to a well-controlled electron spin”, explains Cavendish PhD student, Leon Zaporski – the first author of the paper. “Most researchers approach the problem of isolating qubit from the noise by removing all the interactions. Their qubits become a bit like sedated Schrödinger’s cats, that can barely react to anyone pulling on their tail. Our ‘cat’ is on strong stimulants, which – in practice – means we can have more fun with it.”

    “Quantum dots can now combine high photonic quantum efficiency with long spin coherence times” explains Professor Mete Atatüre, co-author of this paper. “In the near future, we envisage these devices to enable the creation of entangled light states for all-photonic quantum computing and allow foundational quantum control experiments of the nuclear spin ensemble”.

    Nature Nanotechnology

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


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    The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the School of Physical Sciences. The laboratory was opened in 1874 on the New Museums Site as a laboratory for experimental physics and is named after the British chemist and physicist Henry Cavendish. The laboratory has had a huge influence on research in the disciplines of physics and biology.

    As of 2019, 30 Cavendish researchers have won Nobel Prizes. Notable discoveries to have occurred at the Cavendish Laboratory include the discovery of the electron, neutron, and structure of DNA.

    The Cavendish Laboratory was initially located on the New Museums Site, Free School Lane, in the centre of Cambridge. It is named after British chemist and physicist Henry Cavendish for contributions to science and his relative William Cavendish, 7th Duke of Devonshire, who served as chancellor of the university and donated funds for the construction of the laboratory.

    Professor James Clerk Maxwell, the developer of electromagnetic theory, was a founder of the laboratory and the first Cavendish Professor of Physics. The Duke of Devonshire had given to Maxwell, as head of the laboratory, the manuscripts of Henry Cavendish’s unpublished Electrical Works. The editing and publishing of these was Maxwell’s main scientific work while he was at the laboratory. Cavendish’s work aroused Maxwell’s intense admiration and he decided to call the Laboratory (formerly known as the Devonshire Laboratory) the Cavendish Laboratory and thus to commemorate both the Duke and Henry Cavendish.


    Several important early physics discoveries were made here, including the discovery of the electron by J.J. Thomson (1897); the Townsend discharge by John Sealy Townsend and the development of the cloud chamber by C.T.R. Wilson.

    Ernest Rutherford became Director of the Cavendish Laboratory in 1919. Under his leadership the neutron was discovered by James Chadwick in 1932, and in the same year the first experiment to split the nucleus in a fully controlled manner was performed by students working under his direction; John Cockcroft and Ernest Walton.

    Physical chemistry

    Physical Chemistry (originally the department of Colloid Science led by Eric Rideal) had left the old Cavendish site, subsequently locating as the Department of Physical Chemistry (under RG Norrish) in the then new chemistry building with the Department of Chemistry (led by Lord Todd) in Lensfield Road: both chemistry departments merged in the 1980s.

    Nuclear physics

    In World War II the laboratory carried out research for the MAUD Committee, part of the British Tube Alloys project of research into the atomic bomb. Researchers included Nicholas Kemmer, Alan Nunn May, Anthony French, Samuel Curran and the French scientists including Lew Kowarski and Hans von Halban. Several transferred to Canada in 1943; the Montreal Laboratory and some later to the Chalk River Laboratories. The production of plutonium and neptunium by bombarding uranium-238 with neutrons was predicted in 1940 by two teams working independently: Egon Bretscher and Norman Feather at the Cavendish and Edwin M. McMillan and Philip Abelson at Berkeley Radiation Laboratory at The University of California-Berkeley.


    The Cavendish Laboratory has had an important influence on biology, mainly through the application of X-ray crystallography to the study of structures of biological molecules. Francis Crick already worked in the Medical Research Council Unit, headed by Max Perutz and housed in the Cavendish Laboratory, when James Watson came from the United States and they made a breakthrough in discovering the structure of DNA. For their work while in the Cavendish Laboratory, they were jointly awarded the Nobel Prize in Physiology or Medicine in 1962, together with Maurice Wilkins of King’s College London (UK), himself a graduate of St. John’s College, Cambridge.

    The discovery was made on 28 February 1953; the first Watson/Crick paper appeared in Nature on 25 April 1953. Sir Lawrence Bragg, the director of the Cavendish Laboratory, where Watson and Crick worked, gave a talk at Guy’s Hospital Medical School in London on Thursday 14 May 1953 which resulted in an article by Ritchie Calder in The News Chronicle of London, on Friday 15 May 1953, entitled Why You Are You. Nearer Secret of Life. The news reached readers of The New York Times the next day; Victor K. McElheny, in researching his biography, Watson and DNA: Making a Scientific Revolution, found a clipping of a six-paragraph New York Times article written from London and dated 16 May 1953 with the headline Form of `Life Unit’ in Cell Is Scanned. The article ran in an early edition and was then pulled to make space for news deemed more important. (The New York Times subsequently ran a longer article on 12 June 1953). The Cambridge University undergraduate newspaper Varsity also ran its own short article on the discovery on Saturday 30 May 1953. Bragg’s original announcement of the discovery at a Solvay Conference on proteins in Belgium on 8 April 1953 went unreported by the British press.

    Sydney Brenner, Jack Dunitz, Dorothy Hodgkin, Leslie Orgel, and Beryl M. Oughton, were some of the first people in April 1953 to see the model of the structure of DNA, constructed by Crick and Watson; at the time they were working at The University of Oxford (UK)’s Chemistry Department. All were impressed by the new DNA model, especially Brenner who subsequently worked with Crick at Cambridge in the Cavendish Laboratory and the new Laboratory of Molecular Biology. According to the late Dr. Beryl Oughton, later Rimmer, they all travelled together in two cars once Dorothy Hodgkin announced to them that they were off to Cambridge to see the model of the structure of DNA. Orgel also later worked with Crick at The Salk Institute for Biological Studies.

    U Cambridge Campus

    The University of Cambridge (UK) [legally The Chancellor, Masters, and Scholars of the University of Cambridge] is a collegiate public research university in Cambridge, England. Founded in 1209 Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford(UK) after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 semi-autonomous constituent colleges and over 150 academic departments, faculties and other institutions organised into six schools. All the colleges are self-governing institutions within the university, each controlling its own membership and with its own internal structure and activities. All students are members of a college. Cambridge does not have a main campus and its colleges and central facilities are scattered throughout the city. Undergraduate teaching at Cambridge is organised around weekly small-group supervisions in the colleges – a feature unique to the Oxbridge system. These are complemented by classes, lectures, seminars, laboratory work and occasionally further supervisions provided by the central university faculties and departments. Postgraduate teaching is provided predominantly centrally.

    Cambridge University Press a department of the university is the oldest university press in the world and currently the second largest university press in the world. Cambridge Assessment also a department of the university is one of the world’s leading examining bodies and provides assessment to over eight million learners globally every year. The university also operates eight cultural and scientific museums, including the Fitzwilliam Museum, as well as a botanic garden. Cambridge’s libraries – of which there are 116 – hold a total of around 16 million books, around nine million of which are in Cambridge University Library, a legal deposit library. The university is home to – but independent of – the Cambridge Union – the world’s oldest debating society. The university is closely linked to the development of the high-tech business cluster known as “Silicon Fe”. It is the central member of Cambridge University Health Partners, an academic health science centre based around the Cambridge Biomedical Campus.

    By both endowment size and consolidated assets Cambridge is the wealthiest university in the United Kingdom. In the fiscal year ending 31 July 2019, the central university – excluding colleges – had a total income of £2.192 billion of which £592.4 million was from research grants and contracts. At the end of the same financial year the central university and colleges together possessed a combined endowment of over £7.1 billion and overall consolidated net assets (excluding “immaterial” historical assets) of over £12.5 billion. It is a member of numerous associations and forms part of the ‘golden triangle’ of English universities.

    Cambridge has educated many notable alumni including eminent mathematicians; scientists; politicians; lawyers; philosophers; writers; actors; monarchs and other heads of state. As of October 2020 121 Nobel laureates; 11 Fields Medalists; 7 Turing Award winners; and 14 British prime ministers have been affiliated with Cambridge as students; alumni; faculty or research staff. University alumni have won 194 Olympic medals.


    By the late 12th century the Cambridge area already had a scholarly and ecclesiastical reputation due to monks from the nearby bishopric church of Ely. However it was an incident at Oxford which is most likely to have led to the establishment of the university: three Oxford scholars were hanged by the town authorities for the death of a woman without consulting the ecclesiastical authorities who would normally take precedence (and pardon the scholars) in such a case; but were at that time in conflict with King John. Fearing more violence from the townsfolk scholars from the University of Oxford started to move away to cities such as Paris; Reading; and Cambridge. Subsequently enough scholars remained in Cambridge to form the nucleus of a new university when it had become safe enough for academia to resume at Oxford. In order to claim precedence it is common for Cambridge to trace its founding to the 1231 charter from Henry III granting it the right to discipline its own members (ius non-trahi extra) and an exemption from some taxes; Oxford was not granted similar rights until 1248.

    A bull in 1233 from Pope Gregory IX gave graduates from Cambridge the right to teach “everywhere in Christendom”. After Cambridge was described as a studium generale in a letter from Pope Nicholas IV in 1290 and confirmed as such in a bull by Pope John XXII in 1318 it became common for researchers from other European medieval universities to visit Cambridge to study or to give lecture courses.

    Foundation of the colleges

    The colleges at the University of Cambridge were originally an incidental feature of the system. No college is as old as the university itself. The colleges were endowed fellowships of scholars. There were also institutions without endowments called hostels. The hostels were gradually absorbed by the colleges over the centuries; but they have left some traces, such as the name of Garret Hostel Lane.

    Hugh Balsham, Bishop of Ely, founded Peterhouse – Cambridge’s first college in 1284. Many colleges were founded during the 14th and 15th centuries but colleges continued to be established until modern times. There was a gap of 204 years between the founding of Sidney Sussex in 1596 and that of Downing in 1800. The most recently established college is Robinson built in the late 1970s. However Homerton College only achieved full university college status in March 2010 making it the newest full college (it was previously an “Approved Society” affiliated with the university).

    In medieval times many colleges were founded so that their members would pray for the souls of the founders and were often associated with chapels or abbeys. The colleges’ focus changed in 1536 with the Dissolution of the Monasteries. Henry VIII ordered the university to disband its Faculty of Canon Law and to stop teaching “scholastic philosophy”. In response, colleges changed their curricula away from canon law and towards the classics; the Bible; and mathematics.

    Nearly a century later the university was at the centre of a Protestant schism. Many nobles, intellectuals and even commoners saw the ways of the Church of England as too similar to the Catholic Church and felt that it was used by the Crown to usurp the rightful powers of the counties. East Anglia was the centre of what became the Puritan movement. In Cambridge the movement was particularly strong at Emmanuel; St Catharine’s Hall; Sidney Sussex; and Christ’s College. They produced many “non-conformist” graduates who, greatly influenced by social position or preaching left for New England and especially the Massachusetts Bay Colony during the Great Migration decade of the 1630s. Oliver Cromwell, Parliamentary commander during the English Civil War and head of the English Commonwealth (1649–1660), attended Sidney Sussex.

    Modern period

    After the Cambridge University Act formalised the organisational structure of the university the study of many new subjects was introduced e.g. theology, history and modern languages. Resources necessary for new courses in the arts architecture and archaeology were donated by Viscount Fitzwilliam of Trinity College who also founded the Fitzwilliam Museum. In 1847 Prince Albert was elected Chancellor of the University of Cambridge after a close contest with the Earl of Powis. Albert used his position as Chancellor to campaign successfully for reformed and more modern university curricula, expanding the subjects taught beyond the traditional mathematics and classics to include modern history and the natural sciences. Between 1896 and 1902 Downing College sold part of its land to build the Downing Site with new scientific laboratories for anatomy, genetics, and Earth sciences. During the same period the New Museums Site was erected including the Cavendish Laboratory which has since moved to the West Cambridge Site and other departments for chemistry and medicine.

    The University of Cambridge began to award PhD degrees in the first third of the 20th century. The first Cambridge PhD in mathematics was awarded in 1924.

    In the First World War 13,878 members of the university served and 2,470 were killed. Teaching and the fees it earned came almost to a stop and severe financial difficulties followed. As a consequence the university first received systematic state support in 1919 and a Royal Commission appointed in 1920 recommended that the university (but not the colleges) should receive an annual grant. Following the Second World War the university saw a rapid expansion of student numbers and available places; this was partly due to the success and popularity gained by many Cambridge scientists.

  • richardmitnick 6:04 pm on January 28, 2023 Permalink | Reply
    Tags: , , Quantum Computing, , , , , "Danish quantum physicists make nanoscopic advance of colossal significance", Quantum mechanical entanglement, Two light sources can affect each other instantly and potentially across large geographic distances., Using photons as micro transporters to move quantum information about., Entanglement is the very basis of quantum networks and central to the development of an efficient quantum computer.   

    From The Niels Bohr Institute [Niels Bohr Institutet] (DK): “Danish quantum physicists make nanoscopic advance of colossal significance” 

    Niels Bohr Institute bloc

    From The Niels Bohr Institute [Niels Bohr Institutet] (DK)


    University of Copenhagen [Københavns Universitet] [UCPH] (DK)

    Peter Lodahl
    Niels Bohr Institute
    University of Copenhagen
    Mobile: + 45 20 56 53 03
    Email: lodahl@nbi.ku.dk

    Alexey Tiranov
    Niels Bohr Institute
    University of Copenhagen
    Phone: + 45 35 33 51 39
    Email: alexey.tiranov@nbi.ku.dk

    Michael Skov Jensen
    Journalist and team coordinator
    The Faculty of Science
    University of Copenhagen
    Mobile: + 45 93 56 58 97

    In a new breakthrough, researchers at the University of Copenhagen, in collaboration with Ruhr University Bochum, have solved a problem that has caused quantum researchers headaches for years. The researchers can now control two quantum light sources rather than one. Trivial as it may seem to those uninitiated in quantum, this colossal breakthrough allows researchers to create a phenomenon known as quantum mechanical entanglement. This in turn, opens new doors for companies and others to exploit the technology commercially.

    Part of the team behind the invention. From left: Peter Lodahl, Anders Sørensen, Vasiliki Angelopoulou, Ying Wang, Alexey Tiranov, Cornelis van Diepen. Photo: Ola J. Joensen.

    Going from one to two is a minor feat in most contexts. But in the world of quantum physics, doing so is crucial. For years, researchers around the world have strived to develop stable quantum light sources and achieve the phenomenon known as quantum mechanical entanglement – a phenomenon, with nearly sci-fi-like properties, where two light sources can affect each other instantly and potentially across large geographic distances. Entanglement is the very basis of quantum networks and central to the development of an efficient quantum computer.

    Today, researchers from the Niels Bohr Institute published a new result in the highly esteemed journal Science [below], in which they succeeded in doing just that. According to Professor Peter Lodahl, one of the researchers behind the result, it is a crucial step in the effort to take the development of quantum technology to the next level and to “quantize” society’s computers, encryption and the internet.

    “We can now control two quantum light sources and connect them to each other. It might not sound like much, but it’s a major advancement and builds upon the past 20 years of work. By doing so, we’ve revealed the key to scaling up the technology, which is crucial for the most ground-breaking of quantum hardware applications,” says Professor Peter Lodahl, who has conducted research the area since 2001.

    The magic all happens in a so-called nanochip – which is not much larger than the diameter of a human hair – that the researchers also developed in recent years.

    Illustration of two a chip comprising two entangled quantum light sources. Credit: NBI.

    Quantum sources overtake the world’s most powerful computer

    Peter Lodahl’s group is working with a type of quantum technology that uses light particles, called photons, as micro transporters to move quantum information about.

    While Lodahl’s group is a leader in this discipline of quantum physics, they have only been able to control one light source at a time until now. This is because light sources are extraordinarily sensitive to outside “noise”, making them very difficult to copy. In their new result, the research group succeeded in creating two identical quantum light sources rather than just one.

    “Entanglement means that by controlling one light source, you immediately affect the other. This makes it possible to create a whole network of entangled quantum light sources, all of which interact with one another, and which you can get to perform quantum bit operations in the same way as bits in a regular computer, only much more powerfully,” explains postdoc Alexey Tiranov, the article’s lead author.

    This is because a quantum bit can be both a 1 and 0 at the same time, which results in processing power that is unattainable using today’s computer technology. According to Professor Lodahl, just 100 photons emitted from a single quantum light source will contain more information than the world’s largest supercomputer can process.

    By using 20-30 entangled quantum light sources, there is the potential to build a universal error-corrected quantum computer – the ultimate “holy grail” for quantum technology, that large IT companies are now pumping many billions into.

    Other actors will build upon the research

    According to Lodahl, the biggest challenge has been to go from controlling one to two quantum light sources. Among other things, this has made it necessary for researchers to develop extremely quiet nanochips and have precise control over each light source.

    With the new research breakthrough, the fundamental quantum physics research is now in place. Now it is time for other actors to take the researchers’ work and use it in their quests to deploy quantum physics in a range of technologies including computers, the internet and encryption.

    “It is too expensive for a university to build a setup where we control 15-20 quantum light sources. So, now that we have contributed to understanding the fundamental quantum physics and taken the first step along the way, scaling up further is very much a technological task,” says Professor Lodahl.

    The research was conducted at the Danish National Research Foundation’s “Center of Excellence for Hybrid Quantum Networks (Hy-Q)” and is a collaboration between Ruhr University Bochum in Germany and the the University of Copenhagen’s Niels Bohr Institute.


    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Stem Education Coalition

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.

    Niels Bohr Institute Campus

    The Niels Bohr Institutet (DK) is a research institute of the Københavns Universitet [UCPH] (DK). The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics.

    The Institute was founded in 1921, as the Institute for Theoretical Physics of the Københavns Universitet [UCPH] (DK), by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr’s birth – October 7, 1965 – the Institute officially became The Niels Bohr Institutet (DK). Much of its original funding came from the charitable foundation of the Carlsberg brewery, and later from the Rockefeller Foundation.

    During the 1920s, and 1930s, the Institute was the centre of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes further abroad) often visited the Institute to confer with Bohr on new theories and discoveries. The Copenhagen interpretation of quantum mechanics is named after work done at the Institute during this time.

    On January 1, 1993 the institute was fused with the Astronomic Observatory, the Ørsted Laboratory and the Geophysical Institute. The new resulting institute retained the name Niels Bohr Institutet (DK).

    Københavns Universitet (UCPH) (DK) is the oldest university and research institution in Denmark. Founded in 1479 as a studium generale, it is the second oldest institution for higher education in Scandinavia after Uppsala University (1477). The university has 23,473 undergraduate students, 17,398 postgraduate students, 2,968 doctoral students and over 9,000 employees. The university has four campuses located in and around Copenhagen, with the headquarters located in central Copenhagen. Most courses are taught in Danish; however, many courses are also offered in English and a few in German. The university has several thousands of foreign students, about half of whom come from Nordic countries.

    The university is a member of the International Alliance of Research Universities (IARU), along with University of Cambridge (UK), Yale University , The Australian National University (AU), and University of California-Berkeley , amongst others. The 2016 Academic Ranking of World Universities ranks the University of Copenhagen as the best university in Scandinavia and 30th in the world, the 2016-2017 Times Higher Education World University Rankings as 120th in the world, and the 2016-2017 QS World University Rankings as 68th in the world. The university has had 9 alumni become Nobel laureates and has produced one Turing Award recipient.

  • richardmitnick 2:42 pm on January 24, 2023 Permalink | Reply
    Tags: "Quantum simulators": quantum devices tailored to solve specific problems, "Randomness in Quantum Machines Helps Verify Their Accuracy", A new method to verify the accuracy of quantum devices, A single microscopic error leads to a completely different macroscopic outcome-quite similar to the butterfly effect., , Demonstrating a novel way to measure a quantum device's accuracy, Looking for deviations in the patterns that indicate errors have been made, New error-detection method takes advantage of the way quantum information is scrambled., One challenge in using these quantum machines is that they are very prone to errors., Quantum Computing, , , Scientists don't want just a result from our quantum machines; they want a verified result., , The key to the new strategy is randomness.   

    From The California Institute of Technology: “Randomness in Quantum Machines Helps Verify Their Accuracy” 

    Caltech Logo

    From The California Institute of Technology

    Whitney Clavin
    (626) 395‑1944

    New error-detection method takes advantage of the way quantum information is scrambled.

    Researchers have discovered that complex random behaviors naturally emerge from even the simplest, chaotic dynamics in a quantum simulator. This illustration zooms into one such complex set of states within an apparently smooth quantum system. Credit: Adam Shaw.

    In quantum computers and other experimental quantum systems, information spreads around the devices and quickly becomes scrambled like dice in a game of Boggle. This scrambling process happens as the basic units of the system, called qubits (like computer bits only quantum) become entangled with one another; entanglement is a phenomenon in quantum physics where particles link up with each other and remain connected even though they are not in direct contact.

    These quantum devices mimic what happens in nature and allow scientists to develop new, exotic materials that are potentially useful in medicine, computer electronics, and other fields. While full-scale quantum computers are still years away, researchers are already performing experiments on so-called “quantum simulators”: quantum devices tailored to solve specific problems, such as efficiently simulating high-temperature superconductors and other quantum materials. The machines could also solve complex optimization problems, such as planning routes for autonomous vehicles to ensure they don’t collide.

    One challenge in using these quantum machines is that they are very prone to errors, much more so than classical computers. It is also much harder to identify errors in these newer systems. “For the most part, quantum computers make a lot of mistakes,” says Adam Shaw, a Caltech graduate student in physics and one of two lead authors of a study in the journal Nature about a new method to verify the accuracy of quantum devices. “You cannot open the machine and look inside, and there is a huge amount of information being stored—too much for a classical computer to account for and verify.”

    In the Nature study [below], Shaw and co-lead author Joonhee Choi, a former postdoctoral scholar at Caltech who is now a professor at Stanford University, demonstrate a novel way to measure a quantum device’s accuracy, also known as fidelity. Both researchers work in the laboratory of Manuel Endres, a professor of physics at Caltech and a Rosenberg scholar. The key to their new strategy is randomness. The scientists have discovered and characterized a newfound type of randomness pertaining to the way information is scrambled in the quantum systems. But even though the quantum behavior is random, universal statistical patterns can be identified in the noise.

    “We are interested in better understanding what happens when the information is scrambled,” Choi says. “And by analyzing this behavior with statistics, we can look for deviations in the patterns that indicate errors have been made.”

    “We don’t want just a result from our quantum machines; we want a verified result,” Endres says. “Because of quantum chaos, a single microscopic error leads to a completely different macroscopic outcome, quite similar to the butterfly effect. This enables us to detect the error efficiently.”

    The researchers demonstrated their protocol on a quantum simulator with as many as 25 qubits. To find whether errors have occurred, they measured the behavior of the system down to the single qubit level thousands of times. By looking at how qubits evolved over time, the researchers could identify patterns in the seemingly random behavior and then look for deviations from what they expected. Ultimately, by finding errors, researchers will know how and when to fix them.

    “We can trace how information moves across a system with single qubit resolution,” Choi says. “The reason we can do this is that we also discovered that this randomness, which just happens naturally, is represented at the level of just one qubit. You can see the universal random pattern in the subparts of the system.”

    Shaw compares their work to measuring the choppiness of waves on a lake. “If a wind comes, you’ll get peaks and troughs on the lake, and while it may look random, one could identify a pattern to the randomness and track how the wind affects the water. We would be able to tell if the wind changes by analyzing how the pattern changes. Our new method similarly allows us to look for changes in the quantum system that would indicate errors.”

    The Nature study is funded by the National Science Foundation via the Institute for Quantum Information and Matter, or IQIM; the Defense Advanced Research Projects Agency (DARPA); the Army Research Office, the Eddleman Quantum Institute graduate fellowship; the Troesh postdoctoral fellowship; the Gordon and Betty Moore Foundation; the J. Yang & Family Foundation; the Harvard Quantum Initiative (HQI) graduate fellowship; the Junior Fellowship from the Harvard Society of Fellows; the Department of Energy; and the Miller Institute for Basic Research in Science at UC-Berkeley. Other authors include Ran Finkelstein, Hsin-Yuan Huang, and Fernando Brandão of Caltech; Ivaylo Madjarov, Xin Xie, and Jacob Covey, who performed the research while previously at Caltech; Jordan Cotler and Anant Kale of Harvard University; Daniel Mark and Soonwon Choi of MIT; and Hannes Pichler of University of Innsbruck in Austria.

    See the science paper for instructive material with images.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The California Institute of Technology is a private research university in Pasadena, California. The university is known for its strength in science and engineering, and is one among a small group of institutes of technology in the United States which is primarily devoted to the instruction of pure and applied sciences.

    The California Institute of Technology was founded as a preparatory and vocational school by Amos G. Throop in 1891 and began attracting influential scientists such as George Ellery Hale, Arthur Amos Noyes, and Robert Andrews Millikan in the early 20th century. The vocational and preparatory schools were disbanded and spun off in 1910 and the college assumed its present name in 1920. In 1934, The California Institute of Technology was elected to the Association of American Universities, and the antecedents of National Aeronautics and Space Administration ‘s Jet Propulsion Laboratory, which The California Institute of Technology continues to manage and operate, were established between 1936 and 1943 under Theodore von Kármán.

    The California Institute of Technology has six academic divisions with strong emphasis on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. First-year students are required to live on campus, and 95% of undergraduates remain in the on-campus House System at The California Institute of Technology. Although The California Institute of Technology has a strong tradition of practical jokes and pranks, student life is governed by an honor code which allows faculty to assign take-home examinations. The The California Institute of Technology Beavers compete in 13 intercollegiate sports in the NCAA Division III’s Southern California Intercollegiate Athletic Conference (SCIAC).

    As of October 2020, there are 76 Nobel laureates who have been affiliated with The California Institute of Technology, including 40 alumni and faculty members (41 prizes, with chemist Linus Pauling being the only individual in history to win two unshared prizes). In addition, 4 Fields Medalists and 6 Turing Award winners have been affiliated with The California Institute of Technology. There are 8 Crafoord Laureates and 56 non-emeritus faculty members (as well as many emeritus faculty members) who have been elected to one of the United States National Academies. Four Chief Scientists of the U.S. Air Force and 71 have won the United States National Medal of Science or Technology. Numerous faculty members are associated with the Howard Hughes Medical Institute as well as National Aeronautics and Space Administration. According to a 2015 Pomona College study, The California Institute of Technology ranked number one in the U.S. for the percentage of its graduates who go on to earn a PhD.


    The California Institute of Technology is classified among “R1: Doctoral Universities – Very High Research Activity”. Caltech was elected to The Association of American Universities in 1934 and remains a research university with “very high” research activity, primarily in STEM fields. The largest federal agencies contributing to research are National Aeronautics and Space Administration; National Science Foundation; Department of Health and Human Services; Department of Defense, and Department of Energy.

    In 2005, The California Institute of Technology had 739,000 square feet (68,700 m^2) dedicated to research: 330,000 square feet (30,700 m^2) to physical sciences, 163,000 square feet (15,100 m^2) to engineering, and 160,000 square feet (14,900 m^2) to biological sciences.

    In addition to managing NASA-JPL/Caltech , The California Institute of Technology also operates the Caltech Palomar Observatory; The Owens Valley Radio Observatory;the Caltech Submillimeter Observatory; the W. M. Keck Observatory at the Mauna Kea Observatory; the Laser Interferometer Gravitational-Wave Observatory at Livingston, Louisiana and Hanford, Washington; and Kerckhoff Marine Laboratory in Corona del Mar, California. The Institute launched the Kavli Nanoscience Institute at The California Institute of Technology in 2006; the Keck Institute for Space Studies in 2008; and is also the current home for the Einstein Papers Project. The Spitzer Science Center, part of the Infrared Processing and Analysis Center located on The California Institute of Technology campus, is the data analysis and community support center for NASA’s Spitzer Infrared Space Telescope [no longer in service].

    The California Institute of Technology partnered with University of California at Los Angeles to establish a Joint Center for Translational Medicine (UCLA-Caltech JCTM), which conducts experimental research into clinical applications, including the diagnosis and treatment of diseases such as cancer.

    The California Institute of Technology operates several Total Carbon Column Observing Network stations as part of an international collaborative effort of measuring greenhouse gases globally. One station is on campus.

  • richardmitnick 5:11 pm on January 23, 2023 Permalink | Reply
    Tags: "Quantum researchers strike the right chord with silicides", , "Transmon qubit" — a patterned chip made of metallic niobium layers on top of a substrate such as silicon., , In the greater context of the SQMS Center’s aim to develop a state-of-the-art quantum computer the results have much further implications than just understanding the properties of materials., , Quantum Computing, Quantum information in a transmon qubit exists for a limited time before it dissipates or is obscured by environmental noise., Silicides are detrimental to the performance of transmon qubits., The community working on superconducting qubits has traditionally been quantum physicists and engineers. The reason they have been so successful is they’ve embraced material scientists., The compounds of this layer are known as silicides (NbxSiy).,   

    From The DOE’s Fermi National Accelerator Laboratory: “Quantum researchers strike the right chord with silicides” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From The DOE’s Fermi National Accelerator Laboratory-an enduring source of strength for the US contribution to scientific research worldwide.

    Maxwell Bernstein

    Just as the sound of a guitar depends on its strings and the materials used for its body, the performance of a quantum computer depends on the composition of its building blocks. Arguably the most critical components are the devices that encode information in quantum computers.

    One such device is the “transmon qubit” — a patterned chip made of metallic niobium layers on top of a substrate such as silicon. Between the two materials resides an ultrathin layer that contains both niobium and silicon. The compounds of this layer are known as silicides (NbxSiy). Their impact on the performance of transmon qubits has not been well understood — until now.

    The silicide research team. In the front from left to right: Mark Hersam, Michael Bedzyk, James Ronidnelli and Xiezeng Lu. Back: Carlos Torres and Dominic Goronzy. Photo: SQMS Center.

    Silicides form when elemental niobium is deposited onto silicon during the fabrication process of a transmon qubit. They need to be well understood to make devices that reliably and efficiently store quantum information for as long as possible.

    Researchers at the Superconducting Quantum Materials and Systems Center, hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory, have discovered how silicides impact the performance of transmon qubits. Their research has been published in APS Physical Review Materials [below].

    An unexpected signal

    Carlos Torres-Castanedo was analyzing the materials of a transmon qubit using x-rays, when he came across a peculiar signal.

    “I thought the signal came from a surface oxide, because that’s just what usually happens,” said Torres-Castanedo, a doctoral candidate in materials science at Northwestern University. “After spending a day trying to fit the data to match an oxide, the only possibility was to introduce a niobium silicide layer. When the data beautifully fit the model, I showed the results to my co-workers, and we all became excited about what this could mean for transmon qubit performance.”

    The SQMS Center researchers dug deeper. They identified the types of silicides present, the thickness of the layer — typically only a few nanometers thick — and its physical and chemical structure. After completing these measurements, they focused on figuring out how these compounds affect the performance of qubits.

    The researchers simulated different types of silicides. Not only did they find that silicides are detrimental to the performance of transmon qubits, but they also found that some are more detrimental than others.

    Impact on coherence time

    Qubits are the basic and fragile units of information that a quantum computer uses to perform calculations. They are physically encoded through transmon qubits.

    Similar to a street performer plucking an A note on a guitar string and allowing the tone to ring out before it becomes obscured by street noise, quantum information in a transmon qubit exists for a limited time before it dissipates or is obscured by environmental noise. This time span is known as the coherence time. The longer the coherence time, the better the performance of the transmon qubit.

    “This interface will never be like silicon stop, niobium start,” said SQMS Center researcher James Rondinelli, Walter Dill Scott Professor of Materials Science and Engineering at Northwestern University. “The first observation was that there is not an atomically sharp interface, but rather a compositional gradient between the silicon substrate —which is the platform for the system — and the niobium.”

    With that observation, Rondinelli and his group began a detailed computational study as part of a greater SQMS Center effort to improve qubit coherence times.

    Simulations with a supercomputer

    With a newfound curiosity about what the presence of silicides could mean for transmon qubits, the researchers used a supercomputer at the National Energy Research Scientific Computing Center, located at the DOE’s Lawrence Berkley National Laboratory.

    Think of silicides as a thin material inside the street performer’s guitar that affects the sound of the guitar string. Researchers studying transmon qubits are essentially trying to isolate an A note and seeing to what extent the hidden material interferes.

    Some silicides, for example, have magnetic properties that can interfere with the quantum information that rings out from the transmon qubit. The stronger the magnetism, the more the quantum information is obscured.

    Through simulations, researchers found that the silicide compound Nb6Si5 does not have any magnetic properties, while Nb5Si3 introduces magnetic noise. If silicides will always be present in transmon qubits, whether researchers like it or not, Nb6Si5 is less detrimental, and scientists will have to make do.

    “I find it interesting how the research on the properties of these silicides have been studied since the ’80s, but never have been understood in a nanometer-sized film,” said Torres-Castanedo. “I feel proud that I was able to work alongside my fellow researchers to conduct this important study.”

    These findings by themselves are significant. In the greater context of the SQMS Center’s aim to develop a state-of-the-art quantum computer, however, the results have much further implications than just understanding the properties of materials.

    “The community who’s worked on superconducting qubits has traditionally been quantum physicists and engineers. The reason the SQMS Center has been so successful is they’ve embraced material scientists,” said Rondinelli. “To really push the field forward, you have to embrace a little bit of an outsider perspective to make an advancement, and we’re optimistic our multidisciplinary approach will solve this challenge.”

    APS Physical Review Materials

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The DOE’s Fermi National Accelerator Laboratory, located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been operated by the Fermi Research Alliance, a joint venture of the University of Chicago, and the Universities Research Association. Fermilab is a part of the Illinois Technology and Research Corridor.

    Fermilab’s Tevatron was a landmark particle accelerator; until the startup in 2008 of the The European Southern Observatory [La Observatorio Europeo Austral][Observatoire européen austral][Europäische Südsternwarte](EU)(CL)[CERN] Large Hadron Collider(CH) near Geneva, Switzerland, it was the most powerful particle accelerator in the world, accelerating antiprotons to energies of 500 GeV, and producing proton-proton collisions with energies of up to 1.6 TeV, the first accelerator to reach one “tera-electron-volt” energy. At 3.9 miles (6.3 km), it was the world’s fourth-largest particle accelerator in circumference. One of its most important achievements was the 1995 discovery of the top quark, announced by research teams using the Tevatron’s CDF and DØ detectors. It was shut down in 2011.

    In addition to high-energy collider physics, Fermilab hosts a series of fixed-target and neutrino experiments, such as The MicroBooNE (Micro Booster Neutrino Experiment),

    NOνA (NuMI Off-Axis νe Appearance)

    and Seaquest


    Completed neutrino experiments include MINOS (Main Injector Neutrino Oscillation Search), MINOS+, MiniBooNE and SciBooNE (SciBar Booster Neutrino Experiment).

    The MiniBooNE detector was a 40-foot (12 m) diameter sphere containing 800 tons of mineral oil lined with 1,520 phototube detectors. An estimated 1 million neutrino events were recorded each year.

    SciBooNE sat in the same neutrino beam as MiniBooNE but had fine-grained tracking capabilities. The NOνA experiment uses, and the MINOS experiment used, Fermilab’s NuMI (Neutrinos at the Main Injector) beam, which is an intense beam of neutrinos that travels 455 miles (732 km) through the Earth to the Soudan Mine in Minnesota and the Ash River, Minnesota, site of the NOνA far detector.

    The ICARUS neutrino experiment was moved from CERN to Fermilab.

    In the public realm, Fermilab is home to a native prairie ecosystem restoration project and hosts many cultural events: public science lectures and symposia, classical and contemporary music concerts, folk dancing and arts galleries. The site is open from dawn to dusk to visitors who present valid photo identification.

    Asteroid 11998 Fermilab is named in honor of the laboratory.

    The DOE’s Fermi National Accelerator Laboratory campus.

    The DOE’s Fermi National Accelerator Laboratory/MINERvA. Photo Reidar Hahn.

    The DOE’s Fermi National Accelerator LaboratoryDAMIC | The Fermilab Cosmic Physics Center.

    The DOE’s Fermi National Accelerator LaboratoryMuon g-2 studio. As muons race around a ring at the Muon g-2 studio, their spin axes twirl, reflecting the influence of unseen particles.

    The DOE’s Fermi National Accelerator Laboratory Short-Baseline Near Detector under construction.

    The DOE’s Fermi National Accelerator Laboratory Mu2e solenoid.

    The Dark Energy Camera [DECam], built at The DOE’s Fermi National Accelerator Laboratory.

    Weston, Illinois, was a community next to Batavia voted out of existence by its village board in 1966 to provide a site for Fermilab.

    The laboratory was founded in 1969 as the National Accelerator Laboratory; it was renamed in honor of Enrico Fermi in 1974. The laboratory’s first director was Robert Rathbun Wilson, under whom the laboratory opened ahead of time and under budget. Many of the sculptures on the site are of his creation. He is the namesake of the site’s high-rise laboratory building, whose unique shape has become the symbol for Fermilab and which is the center of activity on the campus.

    After Wilson stepped down in 1978 to protest the lack of funding for the lab, Leon M. Lederman took on the job. It was under his guidance that the original accelerator was replaced with the Tevatron, an accelerator capable of colliding protons and antiprotons at a combined energy of 1.96 TeV. Lederman stepped down in 1989. The science education center at the site was named in his honor.

    The later directors include:

    John Peoples, 1989 to 1996
    Michael S. Witherell, July 1999 to June 2005
    Piermaria Oddone, July 2005 to July 2013
    Nigel Lockyer, September 2013 to the present

    Fermilab continues to participate in the work at the Large Hadron Collider (LHC); it serves as a Tier 1 site in the Worldwide LHC Computing Grid and hosts 1000 U.S. scientists who work on the CMS project.

    FNAL Icon

  • richardmitnick 1:51 pm on January 23, 2023 Permalink | Reply
    Tags: "New Swedish quantum computer to be made available to industry", A copy of this quantum computer will be built using funding from the Knut and Alice Wallenberg Foundation thus making the technology available to Swedish industry and Swedish researchers., , Quantum Computing, The Chalmers quantum computer now has 25 quantum bits-or qubits. The target is 100 qubits by 2029 but even with 25 bits running quantum algorithms on the computer is interesting., , The quantum computer will be upgraded to 40 qubits within a couple of years.   

    From The Chalmers University of Technology [Chalmers tekniska högskola](SE): “New Swedish quantum computer to be made available to industry” 

    From The Chalmers University of Technology [Chalmers tekniska högskola](SE)

    Per Delsing
    Director of Wallenberg Centre for Quantum Technology (WACQT)
    Professor at the Department of Microtechnology and Nanoscience
    Chalmers University of Technology, Sweden
    +46 31 772 33 17

    Opening the last stage of the dilution refrigerator for the quantum computer at Chalmers University of Technology in Sweden. A copy of this quantum computer will be built using SEK 102 million in funding from the Knut and Alice Wallenberg Foundation, thus making the technology available to Swedish industry and Swedish researchers. Pictured: Hang-Xi Li, doctoral student and Giovanna Tancredi, research leader of the quantum computer project. Images: Anna-Lena Lundqvist |Chalmers.

    A Swedish quantum computer is to become more widely available. A copy of the quantum computer at Chalmers University of Technology in Sweden will be built using additional funding from the Knut and Alice Wallenberg Foundation. The new computer, accompanied by a quantum helpdesk, will allow Swedish companies and researchers to solve problems using quantum technology.

    ​Under the Wallenberg Centre for Quantum Technology (WACQT) initiative, since 2018 a large project to develop and build a Swedish quantum computer has been running at Chalmers University of Technology. The Chalmers quantum computer now has 25 quantum bits, or qubits. The target is 100 qubits by 2029 but, even with 25 bits, running quantum algorithms on the computer is interesting. The problem is that the machine is rarely available, as researchers are constantly working to develop it.

    “We’re therefore going to build a copy of our quantum computer and make it available as a test bed for companies and researchers to run algorithms. Its purpose is to raise Sweden’s competence level in quantum technology and lower the threshold for using quantum computers,” says Per Delsing, a professor at Chalmers and director of WACQT.

    Optimize the algorithms for the hardware

    “Another big difference is that we’re transparent with what’s under the hood of our quantum computers. That allows you to optimize the algorithms for the hardware, thus increasing the chance of successful computations,” explains Delsing.
    In 2024, the test bed will open its equipment for testing components and the Quantum Helpdesk, while the quantum computer will open for running algorithms in 2025. Initially, the quantum computer will have 25 qubits, but will be upgraded to 40 qubits within a couple of years.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Chalmers University of Technology [Chalmers tekniska högskola](SE) is a Swedish university located in Gothenburg that focuses on research and education in technology, natural science, architecture, maritime and other management areas.

    The University was founded in 1829 following a donation by William Chalmers, a director of the Swedish East India Company. He donated part of his fortune for the establishment of an “industrial school”. Chalmers was run as a private institution until 1937, when the institute became a state-owned university. In 1994, the school was incorporated as an “aktiebolag” under the control of the Swedish Government, the faculty and the Student Union. Chalmers is one of only three universities in Sweden which are named after a person, the other two being Karolinska Institute [Karolinska Institutet] (SE) and Linaeus University [Linnéuniversitetet] (SE) .


    Beginning 1 May 2017, Chalmers has 13 departments.

    Architecture and Civil Engineering
    Biology and Biological Engineering
    Chemistry and Chemical Engineering
    Communication and Learning in Science
    Computer Science and Engineering
    Electrical Engineering
    Industrial and Materials Science
    Mathematical Sciences
    Mechanics and Maritime Sciences
    Microtechnology and Nanoscience
    Space, Earth and Environment
    Technology Management and Economics

    Furthermore, Chalmers is home to eight Areas of Advance and six national competence centers in key fields such as materials, mathematical modelling, environmental science, and vehicle safety.

    Research infrastructure

    Chalmers University of Technology’s research infrastructure includes everything from advanced real or virtual labs to large databases, computer capacity for large-scale calculations and research facilities.

    Chalmers AI Research Centre, CHAIR
    Chalmers Centre for Computational Science and Engineering, C3SE
    Chalmers Mass Spectrometry Infrastructure, CMSI
    Chalmers Power Central
    Chalmers Materials Analysis Laboratory
    Chalmers Simulator Centre
    Chemical Imaging Infrastructure
    Facility for Computational Systems Biology
    HSB Living Lab
    Nanofabrication Laboratory
    Onsala Space Observatory
    Revere – Chalmers Resource for Vehicle Research
    The National laboratory in terahertz characterization
    SAFER – Vehicle and Traffic Safety Centre at Chalmers

    Rankings and reputation

    Since 2012, Chalmers has been achieved the highest reputation for Swedish Universities by the Kantar Sifo’s Reputation Index. According to the survey, Chalmers is the most well-known university in Sweden regarded as a successful and competitive high-class institution with a large contribution to society and credibility in media.

    In 2018, a benchmarking report from The Massachusetts Institute of Technology ranked Chalmers top 10 in the world of engineering education while in 2019, the European Commission recognized Chalmers as one of Europe’s top universities, based on the U-Multirank rankings.

    Furthermore, in 2020, the World University Research Rankings placed Chalmers 12th in the world based on the evaluation of three key research aspects, namely research multi-disciplinarity, research impact, and research cooperativeness, while the QS World University Rankings, placed Chalmers 81st in the world in graduate employability.

    Additionally, in 2021, the Academic Ranking of World Universities, placed Chalmers 51–75 in the world in the field of electrical & electronic engineering, the QS World University Rankings placed Chalmers 79th in the world in the field of engineering & technology. The Times Higher Education World University Rankings ranked Chalmers 68th in the world for engineering & technology and the U.S. News & World Report Best Global University Ranking placed Chalmers 84th in the world for engineering.

    In the 2011 International Professional Ranking of Higher Education Institutions which is established on the basis of the number of alumni holding a post of Chief Executive Officer (CEO) or equivalent in one of the Fortune Global 500 companies Chalmers ranked 38th in the world, ranking 1st in Sweden and 15th in Europe.

    Ties and partnerships

    Chalmers has partnerships with major industries mostly in the Gothenburg region such as Ericsson, Volvo, and SKF. The University has general exchange agreements with many European and U.S. universities and maintains a special exchange program agreement with National Chiao Tung University [國立交通大學](TW) where the exchange students from the two universities maintain offices for, among other things, helping local students with applying and preparing for an exchange year as well as acting as representatives. It contributes also to the Top Industrial Managers for Europe (TIME) network.

    A close collaboration between the Department of Computer Science and Engineering at Chalmers and ICVR at The Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich] (CH) is being established. As of 2014, Chalmers University of Technology is a member of the IDEA League network.

  • richardmitnick 8:30 am on January 23, 2023 Permalink | Reply
    Tags: "IonQ to open the first Quantum Computing Manufacturing plant in Seattle", , Quantum Computing   

    From “Quantum Zeitgeist” : “IonQ to open the first Quantum Computing Manufacturing plant in Seattle” 

    From “Quantum Zeitgeist”

    Kyrlynn D

    IonQ, a leader in ion trap quantum computing, has announced its plans to open the first manufacturing plant specialized in producing quantum computers in Seattle.

    IonQ’s expanding R&D and manufacturing team will be based in the new building as they continue to develop technologies to fulfil ongoing client demand. The new manufacturing facility will support creating of world-class trapped-ion quantum systems while meeting the increasing demands for quantum computing in commercial applications.

    The site will contain IonQ’s second quantum data centre and be the company’s principal North American production engineering location. Over the next few years, IonQ intends to create thousands of new employment opportunities in the region.

    The 65,000-square-foot facility is in Bothell, Washington, a Seattle suburb home to area tech and pharma companies such as Microsoft, Google, Amazon, Panasonic, and Seattle Genetics, as well as academic institutions such as the University of Washington.

    The opening of a new office in the Pacific Northwest is the latest in a string of events for IonQ. In the year 2022, IonQ and the The DOE’s Pacific Northwest National Laboratory stated that their public-private cooperation had resulted in a sustainable and resilient supply of barium qubits for IonQ’s next generation of barium-based quantum computers.

    Dr Dave Mehuys, IonQ Vice President of Product Engineering, who joined IonQ in March 2022 from a top leadership post at Psiquantum, will oversee the construction of the new facility. Dr Mehuys, who has over two decades of expertise managing systems hardware engineering, module component engineering, customer support, and manufacturing operations, will be instrumental in IonQ’s growth in the region.

    IonQ’s quantum systems are offered on the region’s two largest cloud platforms, Amazon Braket and Azure Quantum. With 25 #AQ, IonQ Ariabe became the world’s most potent known quantum computer last year. Airbus, GE, Dow Chemistry, Hyundai Motors, the United States Air Force Research Laboratory, and the University of Maryland have all recently announced corporate and federal contracts.

    See the full article here.

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Quantum Zeitgeist is the original online publication for Quantum Computing News, Quantum technology Features and Articles on the Quantum Industry around the globe.

    Quantum Computing is perhaps one of the most revolutionary technologies of our time and could change multiple industries and the fabric of our world, affecting us all.

    Quantum Technologies are not just about computing but represent new ways to exchange data in quantum Security, Quantum encryption and the Quantum internet.

    See how Quantum is progressing towards a Qubit Future.

  • richardmitnick 11:14 am on January 16, 2023 Permalink | Reply
    Tags: "10 Quantum Leaders running Quantum Computing Companies", , 1. CEO of Quantinuum: Ilyas Khan, 10. Manager Amazon Braket: Richard Moulds, 2. CEO of Xanadu: Christian Weedbrook, 3. CEO of Strangeworks: William Hurley, 4. CEO Riverlane: Steve Brierley, 5. Director IBM Research: Darío Gil, 6. CEO of PsiQuantum: Jeremy O’Brien, 7. CEO Q-CTRL: Michael J. Biercuk, 8. CEO Turing: Seth Lloyd, 9. CEO Horizon Quantum Computing: Joe Fitzsimons, , Quantum Computing   

    From “Quantum Zeitgeist” : “10 Quantum Leaders running Quantum Computing Companies” 

    From “Quantum Zeitgeist”


    Leading a Quantum Computing Company is far from easy. Unlike many companies with easily proven case studies, quantum computing has yet to hit maturity. Many businesses are exploring use cases, and we see the potential applications. Therefore, the environment makes it challenging to run a quantum tech business. It requires persistence in an ever-changing climate of different technologies and claims; navigating the business environment calls for something different. Here we introduce ten Quantum Tech Leaders and their companies. Each company has more than enough to write about, so please follow the references if you want to learn more about what they do.

    This is not an exhaustive list nor a list of the top 10 quantum computing companies. Instead, it aims to pick out leading quantum computing companies and the people behind making that vision a success. For a list of over a hundred quantum computing companies, you can see a general list, and we have specified and introduced the Quantum 10 UK and the Quantum 20 UK, which list quantum computing companies in that territory.

    CEO of Quantinuum: Ilyas Khan

    The co-founder of Quantinuum and Cambridge Quantum Computing. before Quantinuum, Ilyas Khan founded the Cambridge (UK) based Quantum Computing Company: CQC for short. CQC was one of the largest dedicated pure-play quantum computing companies, founded relatively early. It was a fast mover in seeing the potential of quantum computing and putting quantum on the map for the UK. It reached a relatively massive headcount long before most of the world even heard about quantum computing. CQC joined forces with Honeywell to become a “full stack” quantum company named Quantinuum in 2021. A smart move which can see it has the vertical integration that very few companies have in the quantum space.

    CQC was one of the most well-funded Quantum companies, focusing on software and QML (Quantum Machine Learning). The company acquires excellent talent, such as Professor Stephen Clark functions as head of Artificial Intelligence, and Bob Coecke, who is one of the notable talents in QNLP (Quantum Natural Language Processing). The company also created a Quantum Language called t | ket>, which improves the efficiency of quantum circuit optimization. This open-source language toolkit can be used in conjunction with the widely used programming language Python. Additionally, it is compatible with Qubit architectures from Honeywell (now Quantinuum), Microsoft, and IBM Q, providing developers with flexibility in their choice of hardware platform. Quantinuum has an aggressive push into the application layer, such as quantum security.

    The origins of Quantuniuum are almost a decade old, which is a long time to be out in front, pushing the envelope of one of the largest quantum computing companies. Illyas is a true innovator and believer, and as a result, he has “pulled” along the rest of the UK Quantum Industry as they see that Britain can innovate, take risks and build something of actual value. Illyas Khan is an excellent speaker and talks at many quantum events and will expound greatly on his experience as both a business and technical leader.

    CEO of Xanadu: Christian Weedbrook

    Xanadu is a full stack Quantum Computing company that develops hardware and software to drive photonic-based quantum computing. Xanadu’s toolsets, such as Penny Lane are used by researchers and quantum developers to build quantum circuits that can run on various hardware. The company is known for its exemplary work on quantum machine learning or QML, which adopted some of the more well-known Quantum Machine Learning researchers, such as Maria Schuld. Xanadu has often been featured in Quantum Zeitgeist and is listed as one of our companies to watch in 2023.

    We love the “Beatles” theme for their products and applaud their commitment to education and inspiring a future quantum generation. They are the hosts for QHack2023 and have run the event in previous years where they create competitions that allow participants to program quantum computers to perform certain tasks. There is help available, prizes, and of course, some call swag for those that enter. The culture of Xanadu comes from the top and is embedded right from the start. Therefore we salute Chris Weedbrook for his dedication to building a quantum computing company and a culture that allows innovation to percolate and spread with a fun theme (such as naming products in a “Beatles” theme).

    Christian Weedbrook is the CEO of Xanadu, which has its headquarters in Toronto, Canada. Christian has plenty of industry, government and formal research experience in quantum computing and cryptography. His education includes, more recently, a postdoc held at MIT, and he obtained his PhD in Physics from the University of Queensland.

    CEO of Strangeworks: William Hurley

    Strangeworks might be an off-sounding company name, but we have always loved the “nod” to the Strangeness of Quantum physics and hence the Moniker. We also commented on the fun culture we can see from both the business and products. The Strangeworks Quantum Computing Platform is a hardware-agnostic, software-inclusive, collaborative development environment.

    Strangeworks also sponsored stack exchange, making the collaboration of quantum ideas and circuits, and disseminating knowledge easier and faster. They integrated such features into their platform to give it a holistic or “one-stop shop” experience where solving the problem becomes the focus. Through the very clever design of their interface, they have made quantum computing concepts much more straightforward. We reported that their design elements for creating circuits are the most elegant we have ever seen.

    Strangeworks founder “Whurley” (a moniker he has used since 2002) does a lot to put Quantum Computing on the map and is frequently found giving addresses to various audiences on Quantum Computing. Whurley is perhaps somewhat unusual in that he doesn’t come from the usual stable of academic innovators. Instead, he is a serial entrepreneur who has made his name in various former ventures before Starngeworks is without a PhD in physics, but is no deterrence. The Quantum Community needs people of all persuasions, especially those who understand critical business applications and how to add value in the field.

    Whurley might be best described as a renaissance man with a repertoire even going across film and design. He received a Design award from Apple in 2004 (ADA), which goes to show that just as Steve Jobs focused on making products that were a delight to use, Whurley might have a different enough take that means that Strangeworks can carve itself out as a real contender for native quantum platforms.

    CEO Riverlane: Steve Brierley

    Having the vision to create an Operating System for quantum computing was never going to be a shy undertaking. Steve Brierley has taken the mission to build the Operating System for error-corrected quantum computers to heart. Hailing from Cambridge, Riverlane was founded in 2016 to accelerate the development of a “useful” quantum computer, a time horizon that was thought to be more than 20 years in the future.

    Riverlane does the “tricky” stuff; perhaps it is not considered the sexiest of tasks compared to interfaces and design, but building that layer that governs hardware is a necessary and important one. We liken it to the fact that today we deal little with computer operating systems, and thankfully so. They are transparent as we go about our tasks and applications, not needing to worry about the hardware. But someone has to build this layer, just as Microsoft made MS-DOS (Microsoft Disk Operating System) to allow innovation in the application layer. Just as Microsoft created the environment to enable computing to flourish, developments from Riverlane can potentially allow Quantum Computing to develop similarly.

    Riverlane’s customers are the hardware companies, universities and governments building a new generation of large, error-corrected quantum computers and organisations. before Riverlane, Steve was a fellow at Cambridge University, of course, quantum science, but he has also been a fellow at Bristol University, which has a fantastic Quantum Research facility.

    Director IBM Research: Darío Gil

    Big Blue is determined not to miss out on the next wave of innovation: Quantum Computing. It has thrown considerable resources behind its push into quantum, being the first to offer cloud-based quantum computing to just about anyone with its IBM Q series. In some ways, IBM was the pathfinder for quantum, which showed the world that it could be serious about Quantum, for here was one of the world’s technology giants getting on onboard with quantum computing. Many quantum computing companies were indeed watching and looking to imitate.

    IBM has consistently proved it can do “full stack” quantum computing. Innovating at the hardware and software levels has shown how it can develop technological innovation but own the quantum agenda. It has consistently brought out processors with ever more significant numbers of qubits and the evermore powerful chip. It has even publicly set itself innovation targets in terms of its roadmaps for its processors. The latest chip delivery saw it bring to life a chip with 433 qubits (just like the bit, the qubit is the quantum equivalent). If the roadmap hold, IBM will deliver over one-thousand qubits this year in 2023. Moore’s law, anyone? IBM is setting the pace and showing the world its innovative days are not behind it. As the creator of the IBM PC, big blue saw company after company take a chunk out of its core business. We think IBM has learned some of those lessons and is almost analogous to Intel (bringing out more powerful chips like a metronome).

    IBM is also behind the most popular quantum computing framework named qiskit. The bizarre-sounding programming language has become almost the standard of the quantum computing development community. A survey showed that it is the most popular, followed by Q# (from Microsoft).

    Gil is no slick salesman. First and foremost, a scientist and innovator. On his watch, IBM was the first company in the world to build programmable quantum computers and make them universally available through the cloud. He will have spurred on generations of enthusiasts and scientists to experiment with quantum computing, and he most likely accelerated the field countless years.

    Darío Gil was originally from Spain but spent his last high school year at Los Altos High near Palo Alto, where you might say he got the bug for innovation and never returned to Spain. A graduate of MIT, he did his PhD there and joined IBM twenty years ago. He leads over 3,000 scientists across more than 20 locations.

    Almost everyone who has shown an interest in Quantum Computing has used IBM Q as it’s an easily accessible platform. It’s making IBM relevant again for the innovators of today and tomorrow, and Darío Gil should be applauded for that. But also, no doubt, amongst the quantum computing companies he has inspired, he may have created competition for IBM in the future.

    CEO of PsiQuantum: Jeremy O’Brien

    Very few companies have raised the sort of sums for quantum computing companies that PsiQuantum has. According to Crunchbase the company has raised $665 million since PsiQuantum’s inception in 2016, which makes it one of the most significant capital raises ever in the quantum space for a pure-play quantum company.

    Jeremy O’Brien is the CEO of PsiQuantum, and was a professor of Physics and Electrical Engineering at the University of Bristol. His specialisms included optical or photonic quantum computing, and he is credited with the invention of the first optical quantum controlled-NOT gate or CNOT. O’Brien completed his PhD at the University of New South Wales in Australia in 2001. His experience goes back to 1995 when he first got interested in Quantum Computing, and since then, he has decided himself to the field.

    The ambition is to deliver a million qubits, and PsiQuantum believes the only way to do it is via photonic systems. Of course, there are alternatives in the market, such as superconducting qubits sported by the likes of IBM. Still, the photonic technology behind PsiQuantum and Xanadu has some benefits of scale, although there is no clear winner as to what will scale fastest. We applaud the ambition because whilst companies have a roadmap, a million qubits are quite an achievement if it happens, although there are no timelines.

    CEO Q-CTRL: Michael J. Biercuk

    Q-CTRL can perhaps best be described as middle-ware. Like Riverlane and their quest for an operating system, Q-CTRL works on the control systems behind the hardware.

    Like all excellent quantum computing companies, Q-Ctrl does more than build stuff. The company also is building an ecosystem. It has one of the best online learning tutorials we have seen, Black Opal, which makes learning the fundamentals of quantum computing a breeze. Q-CTRL is doing the difficult stuff, the bread and butter of the quantum world – so-called enabling technologies. Control theory was crucial in the early days of flight, and it is vital in the quantum sector to solve some of the most complex problems.

    Like many technology leaders, Michael J. Biercuk has many academic credentials, including a Professorship in Quantum Physics and Quantum Technology at the University of Sydney. With a doctorate from Harvard University, Michael has worked on a variety of topics, such as Ion Storage and has worked with DARPA. As an academic, he has published over 65 papers and has eight patents. 2017 saw Biercuk found Q-CTRL based on his research from the Quantum Control Lab.

    CEO Turing: Seth Lloyd

    Seth Lloyd practically created the technology behind commercial operations enabling quantum computing companies such as D-wave, which utilizes Quantum Annealing. No surprise that he was going to start his very own quantum computing company. The original quantum mechanic is a professor of mechanical engineering, but through his work, books and research, he is reaching into the fundamentals of physics and the universe. Seth is also famous for the HHL algorithm, which shows that a quantum computer can factorize a matrix faster than a classical one.

    Turing is a quantum startup founded by Prof. Seth Lloyd and Dr Michele Reilly. According to the latest news, it is focused on some key areas: QKD, essentially entanglement. They see themselves as the enablers of the age of the quantum transistor.

    CEO Horizon Quantum Computing: Joe Fitzsimons

    The team at Horizon want to go one step beyond simply programming quantum computers and make it simple for users to program what they want and run it seamlessly on classical and quantum hardware. The innovation at the core of Horizon’s technology is a process that automatically creates quantum algorithms based on programs written in classical languages. Like today, we might not explicitly need to write for a GPU (Graphical Processing Unit). Perhaps we’ll see the same in the quantum space, where users can get back to focusing on the applications.

    Very few, even professional programmers, could identify the assembly commands required to, say, execute a python conditional statement. That doesn’t stop millions of users from benefitting from a high-level language such as python.

    Dr Joe Fitzsimons gave up his tenured faculty position to found Horizon Quantum Computing in 2018. With over 15 years of experience in quantum computing and computational complexity theory, he is now focused full-time on Horizon. Fitzsimons has spent time in Dublin, Oxford and Singapore. Joe led the Quantum Information and Theory group at the Singapore University of Technology and Design, where he was a tenured associate professor and principal investigator at the Centre for Quantum Technologies.

    We love the mission to make Quantum Computing a general-purpose quantum technology. Making quantum computing truly accessible to everyone could be a world-leading quest, and we like it!

    Manager Amazon Braket: Richard Moulds

    Amazon is perhaps the world’s leader in computing services accessible on the cloud. Since very few people are building quantum computers, it makes sense that the cloud will enable access. It was only time before Amazon and AWS got in on the quantum scene.

    Amazon Braket is just like their other AWS services in being a fully managed quantum computing service. Amazon Braket claims to provide everything you need to build, test, and run quantum algorithms on AWS. It includes access to different types of quantum computers so it should be hardware agnostic but offers a unified development environment.

    Richard Moulds started life as an Electrical Engineer but has moved into management roles. Moulds has an engineering background and an MBA from Warwick. With his commercial background, Richard will be critical in ensuring that AWS brings new quantum companies into their cloud service in the competition against IBM, for example.

    See the full article here.

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Quantum Zeitgeist is the original online publication for Quantum Computing News, Quantum technology Features and Articles on the Quantum Industry around the globe.

    Quantum Computing is perhaps one of the most revolutionary technologies of our time and could change multiple industries and the fabric of our world, affecting us all.

    Quantum Technologies are not just about computing but represent new ways to exchange data in quantum Security, Quantum encryption and the Quantum internet.

    See how Quantum is progressing towards a Qubit Future.

  • richardmitnick 3:06 pm on January 15, 2023 Permalink | Reply
    Tags: "New Algorithm Closes Quantum Supremacy Window", "Quantum error correction", , , Quantum Computing   

    From “Quanta Magazine” : “New Algorithm Closes Quantum Supremacy Window” 

    From “Quanta Magazine”

    Ben Brubaker

    In random circuit sampling, researchers take quantum bits and randomly manipulate them. A new paper explores how errors in quantum computers can multiply to thwart these efforts. Credit: Kristina Armitage and Merrill Sherman/Quanta Magazine.

    In what specific cases do quantum computers surpass their classical counterparts? That’s a hard question to answer, in part because today’s quantum computers are finicky things, plagued with errors that can pile up and spoil their calculations.

    By one measure, of course, they’ve already done it. In 2019, physicists at Google announced that they used a 53-qubit machine to achieve quantum supremacy, a symbolic milestone marking the point at which a quantum computer does something beyond the reach of any practical classical algorithm.

    Similar demonstrations by physicists at the University of Science and Technology of China soon followed.

    But rather than focus on an experimental result for one particular machine, computer scientists want to know whether classical algorithms will be able to keep up as quantum computers get bigger and bigger. “The hope is that eventually the quantum side just completely pulls away until there’s no competition anymore,” said Scott Aaronson, a computer scientist at the University of Texas-Austin.

    That general question is still hard to answer, again in part because of those pesky errors. (Future quantum machines will compensate for their imperfections using a technique called “quantum error correction”, but that capability is still a ways off.) Is it possible to get the hoped-for runaway quantum advantage even with uncorrected errors?

    Most researchers suspected the answer was no, but they couldn’t prove it for all cases. Now, in a paper posted to the preprint server arxiv.org, a team of computer scientists has taken a major step toward a comprehensive proof that error correction is necessary for a lasting quantum advantage in random circuit sampling — the bespoke problem that Google used to show quantum supremacy. They did so by developing a classical algorithm that can simulate random circuit sampling experiments when errors are present.

    “It’s a beautiful theoretical result,” Aaronson said, while stressing that the new algorithm is not practically useful for simulating real experiments like Google’s.

    In random circuit sampling experiments, researchers start with an array of qubits, or quantum bits. They then randomly manipulate these qubits with operations called quantum gates. Some gates cause pairs of qubits to become entangled, meaning they share a quantum state and can’t be described separately. Repeated layers of gates bring the qubits into a more complicated entangled state.

    To learn about that quantum state, researchers then measure all the qubits in the array. This causes their collective quantum state to collapse to a random string of ordinary bits — 0s and 1s. The number of possible outcomes grows rapidly with the number of qubits in the array: With 53 qubits, as in Google’s experiment, it’s nearly 10 quadrillion. And not all strings are equally likely. Sampling from a random circuit means repeating such measurements many times to build up a picture of the probability distribution underlying the outcomes.

    The question of quantum advantage is simply this: Is it hard to mimic that probability distribution with a classical algorithm that doesn’t use any entanglement?

    In 2019, researchers proved [Nature Physics] [below] volume that the answer is yes for error-free quantum circuits: It is indeed hard to classically simulate a random circuit sampling experiment when there are no errors. The researchers worked within the framework of computational complexity theory, which classifies the relative difficulty of different problems. In this field, researchers don’t treat the number of qubits as a fixed number such as 53. “Think of it as n, which is some number that’s going to increase,” said Aram Harrow, a physicist at the Massachusetts Institute of Technology. “Then you want to ask: Are we doing things where the effort is exponential in n or polynomial in n?” This is the preferred way to classify an algorithm’s runtime — when n grows large enough, an algorithm that’s exponential in n lags far behind any algorithm that’s polynomial in n. When theorists speak of a problem that’s hard for classical computers but easy for quantum computers, they’re referring to this distinction: The best classical algorithm takes exponential time, while a quantum computer can solve the problem in polynomial time.

    Yet that 2019 paper ignored the effects of errors caused by imperfect gates. This left open the case of a quantum advantage for random circuit sampling without error correction.

    If you imagine continually increasing the number of qubits as complexity theorists do, and you also want to account for errors, you need to decide whether you’re also going to keep adding more layers of gates — increasing the circuit depth, as researchers say. Suppose you keep the circuit depth constant at, say, a relatively shallow three layers, as you increase the number of qubits. You won’t get much entanglement, and the output will still be amenable to classical simulation. On the other hand, if you increase the circuit depth to keep up with the growing number of qubits, the cumulative effects of gate errors will wash out the entanglement, and the output will again become easy to simulate classically.

    But in between lies a Goldilocks zone. Before the new paper, it was still a possibility that quantum advantage could survive here, even as the number of qubits increased. In this intermediate-depth case, you increase the circuit depth extremely slowly as the number of qubits grows: Even though the output will steadily get degraded by errors, it might still be hard to simulate classically at each step.

    The new paper closes this loophole. The authors derived a classical algorithm for simulating random circuit sampling and proved that its runtime is a polynomial function of the time required to run the corresponding quantum experiment. The result forges a tight theoretical connection between the speed of classical and quantum approaches to random circuit sampling.

    The new algorithm works for a major class of intermediate-depth circuits, but its underlying assumptions break down for certain shallower ones, leaving a small gap where efficient classical simulation methods are unknown. But few researchers are holding out hope that random circuit sampling will prove hard to simulate classically in this remaining slim window. “I give it pretty small odds,” said Bill Fefferman, a computer scientist at the University of Chicago and one of the authors of the 2019 theory paper.

    The result suggests that random circuit sampling won’t yield a quantum advantage by the rigorous standards of computational complexity theory. At the same time, it illustrates the fact that polynomial algorithms, which complexity theorists indiscriminately call efficient, aren’t necessarily fast in practice. The new classical algorithm gets progressively slower as the error rate decreases, and at the low error rates achieved in quantum supremacy experiments, it’s far too slow to be practical. With no errors it breaks down altogether, so this result doesn’t contradict anything researchers knew about how hard it is to classically simulate random circuit sampling in the ideal, error-free case. Sergio Boixo, the physicist leading Google’s quantum supremacy research, says he regards the paper “more as a nice confirmation of random circuit sampling than anything else.”

    On one point, all researchers agree: The new algorithm underscores how crucial quantum error correction will be to the long-term success of quantum computing. “That’s the solution, at the end of the day,” Fefferman said.

    Science paper:
    Nature Physics

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Formerly known as Simons Science News, Quanta Magazine is an editorially independent online publication launched by the Simons Foundation to enhance public understanding of science. Why Quanta? Albert Einstein called photons “quanta of light.” Our goal is to “illuminate science.” At Quanta Magazine, scientific accuracy is every bit as important as telling a good story. All of our articles are meticulously researched, reported, edited, copy-edited and fact-checked.

  • richardmitnick 4:52 pm on January 14, 2023 Permalink | Reply
    Tags: "EDSR": electric dipole spin resonance, "New spin control method brings billion-qubit quantum chips closer", A quantum bit (or qubit) exists in both of these states at once – a condition known as a ‘superposition’. This allows a multitude of computation strategies., , Controlling single electrons without disturbing others nearby is essential for quantum information processing in silicon., Discovery of previously unknown effect makes compact and ultra-fast control of spin qubits possible., Logic gates are the basic building block of all computation. They allow ‘bits’ – or binary digits (0s and 1s) – to work together to process information., Precisely controlling single electrons nestled in quantum dots., Quantum Computing, Qubits themselves are made up of ‘quantum dots’ – tiny nanodevices which can trap one or a few electrons. Precise control of the electrons is necessary for computation to occur., , There are two established methods: electron spin resonance (ESR) using an on-chip microwave antenna; and electric dipole spin resonance (EDSR)., Using electric rather than magnetic fields   

    From The University of New South Wales (AU) : “New spin control method brings billion-qubit quantum chips closer” 

    UNSW bloc

    From The University of New South Wales (AU)


    Discovery of previously unknown effect makes compact and ultra-fast control of spin qubits possible.

    Illustration showing how multiple qubits might be controlled using the new ‘intrinsic spin-orbit EDSR’ process. Image: Tony Melov.

    UNSW Sydney engineers have discovered a new way of precisely controlling single electrons nestled in quantum dots that run logic gates. The new mechanism is also less bulky and requires fewer parts, which could prove essential to making large-scale silicon quantum computers a reality.

    The serendipitous discovery, made by engineers at the quantum computing start-up Diraq and UNSW, is detailed in the journal Nature Nanotechnology [below].

    “This was a completely new effect we’d never seen before, which we didn’t quite understand at first,” said lead author Dr Will Gilbert, a quantum processor engineer at Diraq, a UNSW spin-off company based at its Kensington campus. “But it quickly became clear that this was a powerful new way of controlling spins in a quantum dot. And that was super exciting.”

    Logic gates are the basic building block of all computation. They allow ‘bits’ – or binary digits (0s and 1s) – to work together to process information. However, a quantum bit (or qubit) exists in both of these states at once – a condition known as a ‘superposition’. This allows a multitude of computation strategies – some exponentially faster, some operating simultaneously – that are beyond classical computers. Qubits themselves are made up of ‘quantum dots’ – tiny nanodevices which can trap one or a few electrons. Precise control of the electrons is necessary for computation to occur.

    Using electric rather than magnetic fields

    While experimenting with different geometrical combinations of devices just billionths of a metre in size that control quantum dots, along with various types of miniscule magnets and antennas that drive their operations, Dr Tuomo Tanttu from UNSW Engineering stumbled across a strange effect.

    “I was trying to really accurately operate a two-qubit gate, iterating through a lot of different devices, slightly different geometries, different materials stacks and different control techniques,” said Dr Tanttu, who is also a measurement engineer at Diraq. “Then this strange peak popped up. It looked like the rate of rotation for one of the qubits was speeding up, which I’d never seen in four years of running these experiments.”

    What he had discovered, the engineers later realized, was a new way of manipulating the quantum state of a single qubit by using electric fields, rather than the magnetic fields they had been using previously. Since the discovery was made in 2020, the engineers have been perfecting the technique – which has become another tool in their arsenal to fulfil Diraq’s ambition of building billions of qubits on a single chip.

    “This is a new way to manipulate qubits, and it’s less bulky to build – you don’t need to fabricate cobalt micro-magnets or an antenna right next to the qubits to generate the control effect,” said Dr Gilbert. “It removes the requirement of placing extra structures around each gate. So, there’s less clutter.”

    Controlling single electrons without disturbing others nearby is essential for quantum information processing in silicon. There are two established methods: electron spin resonance (ESR) using an on-chip microwave antenna; and electric dipole spin resonance (EDSR), which relies on an induced gradient magnetic field. The newly discovered technique is known as ‘intrinsic spin-orbit EDSR’.

    “Normally, we design our microwave antennas to deliver purely magnetic fields,” said Dr Tanttu. “But this particular antenna design generated more of an electric field than we wanted – but that turned out to be lucky, because we discovered a new effect we can use to manipulate qubits. That’s serendipity for you.”

    Building on making quantum computing in silicon a reality

    “This is a gem of a new mechanism, which just adds to the trove of proprietary technology we’ve developed over the past 20 years of research,” said Professor Andrew Dzurak, Scientia Professor in Quantum Engineering at UNSW and CEO and founder of Diraq. Professor Dzurak led the team that built the first quantum logic gate in silicon in 2015.

    “It builds on our work to make quantum computing in silicon a reality, based on essentially the same semiconductor component technology as existing computer chips, rather than relying on exotic materials.

    The research team: Professor Andrew Dzurak, Dr Will Gilbert and Dr Tuomo Tanttu. Photo: Grant Turner.

    “Since it’s based on the same CMOS technology as today’s computer industry, our approach will make it easier and faster to scale up for commercial production and achieve our goal of fabricating billions of qubits on a single chip.”

    CMOS (or complementary metal-oxide-semiconductor, pronounced “see-moss”) is the fabrication process at the heart of modern computers. It’s used for making all sorts of integrated circuit components – including microprocessors, microcontrollers, memory chips and other digital logic circuits, as well as analogue circuits such as image sensors and data converters.

    Science paper:
    Nature Nanotechnology

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.

    U NSW Campus

    The University of New South Wales is an Australian public university with its largest campus in the Sydney suburb of Kensington.

    Established in 1949, UNSW is a research university, ranked 44th in the world in the 2021 QS World University Rankings and 67th in the world in the 2021 Times Higher Education World University Rankings. UNSW is one of the founding members of the Group of Eight, a coalition of Australian research-intensive universities, and of Universitas 21, a global network of research universities. It has international exchange and research partnerships with over 200 universities around the world.

    According to the 2021 QS World University Rankings by Subject, UNSW is ranked top 20 in the world for Law, Accounting and Finance, and 1st in Australia for Mathematics, Engineering and Technology. UNSW also leads Australia in Medicine, where the median ATAR (Australian university entrance examination results) of its Medical School students is higher than any other Australian medical school. UNSW enrolls the highest number of Australia’s top 500 high school students academically, and produces more millionaire graduates than any other Australian university.

    The university comprises seven faculties, through which it offers bachelor’s, master’s and doctoral degrees. The main campus is in the Sydney suburb of Kensington, 7 kilometres (4.3 mi) from the Sydney CBD. The creative arts faculty, UNSW Art & Design, is located in Paddington, and subcampuses are located in the Sydney CBD as well as several other suburbs, including Randwick and Coogee. Research stations are located throughout the state of New South Wales.

    The university’s second largest campus, known as UNSW Canberra at ADFA (formerly known as UNSW at ADFA), is situated in Canberra, in the Australian Capital Territory (ACT). ADFA is the military academy of the Australian Defense Force, and UNSW Canberra is the only national academic institution with a defense focus.

    Research centres

    The university has a number of purpose-built research facilities, including:

    UNSW Lowy Cancer Research Centre is Australia’s first facility bringing together researchers in childhood and adult cancers, as well as one of the country’s largest cancer-research facilities, housing up to 400 researchers.
    The Mark Wainwright Analytical Centre is a centre for the faculties of science, medicine, and engineering. It is used to study the structure and composition of biological, chemical, and physical materials.
    UNSW Canberra Cyber is a cyber-security research and teaching centre.
    The Sino-Australian Research Centre for Coastal Management (SARCCM) has a multidisciplinary focus, and works collaboratively with the Ocean University of China [中國海洋大學](CN) in coastal management research.

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