From University of Vienna [Universität Wien] (AT) and From Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich] (CH) via : “Quantum particles- Pulled and compressed”

From University of Vienna [Universität Wien] (AT)


From Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich] (CH)


July 7, 2021

The quantum motion of a nanoparticle can be extended beyond the size of the particle using the new technique developed by. physicists in Austria. Credit: Marc Montagut.

Very recently, researchers led by Markus Aspelmeyer at the University of Vienna and Lukas Novotny at ETH Zürich cooled a glass nanoparticle into the quantum regime for the first time. To do this, the particle is deprived of its kinetic energy with the help of lasers. What remains are movements, so-called quantum fluctuations, which no longer follow the laws of classical physics but those of quantum physics. The glass sphere with which this has been achieved is significantly smaller than a grain of sand, but still consists of several hundred million atoms. In contrast to the microscopic world of photons and atoms, nanoparticles provide an insight into the quantum nature of macroscopic objects. In collaboration with experimental physicist Markus Aspelmeyer, a team of theoretical physicists led by Oriol Romero-Isart of the University of Innsbruck [Leopold-Franzens-Universität Innsbruck] (AT) and the Institute of Quantum Optics and Quantum Information of the Austrian Academy of Sciences [Österreichische Akademie der Wissenschaften](AT) is now proposing a way to harness the quantum properties of nanoparticles for various applications.

Briefly delocalized

“While atoms in the motional ground state bounce around over distances larger than the size of the atom, the motion of macroscopic objects in the ground state is very, very small,” explain Talitha Weiss and Marc Roda-Llordes from the Innsbruck team. “The quantum fluctuations of nanoparticles are smaller than the diameter of an atom.” To take advantage of the quantum nature of nanoparticles, the wave function of the particles must be greatly expanded. In the Innsbruck quantum physicists’ scheme, nanoparticles are trapped in optical fields and cooled to the ground state. By rhythmically changing these fields, the particles now succeed in briefly delocalizing over exponentially larger distances. “Even the smallest perturbations may destroy the coherence of the particles, which is why by changing the optical potentials, we only briefly pull apart the wave function of the particles and then immediately compress it again,” explains Oriol Romero-Isart. By repeatedly changing the potential, the quantum properties of the nanoparticle can thus be harnessed.

Many applications

With the new technique, the macroscopic quantum properties can be studied in more detail. It also turns out that this state is very sensitive to static forces. Thus, the method could enable highly sensitive instruments that can be used to determine forces such as gravity very precisely. Using two particles expanded and compressed simultaneously by this method, it would also be possible to entangle them via a weak interaction and explore entirely new areas of the macroscopic quantum world.

Together with other proposals, the new concept forms the basis for the ERC Synergy Grant project Q-Xtreme, which was granted last year. In this project, the research groups of Markus Aspelmeyer and Oriol Romero-Isart, together with Lukas Novotny and Romain Quidant of ETH Zürich, are pushing one of the most fundamental principles of quantum physics to the extreme limit by positioning a solid body of billions of atoms in two places at the same time.

Science paper:
Physical Review Letters

See the full article here .


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ETH Zurich campus
Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich] (CH) is a public research university in the city of Zürich, Switzerland. Founded by the Swiss Federal Government in 1854 with the stated mission to educate engineers and scientists, the school focuses exclusively on science, technology, engineering and mathematics. Like its sister institution Swiss Federal Institute of Technology in Lausanne [EPFL-École Polytechnique Fédérale de Lausanne](CH) , it is part of the Swiss Federal Institutes of Technology Domain (ETH Domain)) , part of the Swiss Federal Department of Economic Affairs, Education and Research [EAER][Eidgenössisches Departement für Wirtschaft, Bildung und Forschung] [Département fédéral de l’économie, de la formation et de la recherche] (CH).

The university is an attractive destination for international students thanks to low tuition fees of 809 CHF per semester, PhD and graduate salaries that are amongst the world’s highest, and a world-class reputation in academia and industry. There are currently 22,200 students from over 120 countries, of which 4,180 are pursuing doctoral degrees. In the 2021 edition of the QS World University Rankings ETH Zürich is ranked 6th in the world and 8th by the Times Higher Education World Rankings 2020. In the 2020 QS World University Rankings by subject it is ranked 4th in the world for engineering and technology (2nd in Europe) and 1st for earth & marine science.

As of November 2019, 21 Nobel laureates, 2 Fields Medalists, 2 Pritzker Prize winners, and 1 Turing Award winner have been affiliated with the Institute, including Albert Einstein. Other notable alumni include John von Neumann and Santiago Calatrava. It is a founding member of the IDEA League and the International Alliance of Research Universities (IARU) and a member of the CESAER network.

ETH Zürich was founded on 7 February 1854 by the Swiss Confederation and began giving its first lectures on 16 October 1855 as a polytechnic institute (eidgenössische polytechnische Schule) at various sites throughout the city of Zurich. It was initially composed of six faculties: architecture, civil engineering, mechanical engineering, chemistry, forestry, and an integrated department for the fields of mathematics, natural sciences, literature, and social and political sciences.

It is locally still known as Polytechnikum, or simply as Poly, derived from the original name eidgenössische polytechnische Schule, which translates to “federal polytechnic school”.

ETH Zürich is a federal institute (i.e., under direct administration by the Swiss government), whereas the University of Zürich [Universität Zürich ] (CH) is a cantonal institution. The decision for a new federal university was heavily disputed at the time; the liberals pressed for a “federal university”, while the conservative forces wanted all universities to remain under cantonal control, worried that the liberals would gain more political power than they already had. In the beginning, both universities were co-located in the buildings of the University of Zürich.

From 1905 to 1908, under the presidency of Jérôme Franel, the course program of ETH Zürich was restructured to that of a real university and ETH Zürich was granted the right to award doctorates. In 1909 the first doctorates were awarded. In 1911, it was given its current name, Eidgenössische Technische Hochschule. In 1924, another reorganization structured the university in 12 departments. However, it now has 16 departments.

ETH Zürich, EPFL (Swiss Federal Institute of Technology in Lausanne) [École polytechnique fédérale de Lausanne](CH), and four associated research institutes form the Domain of the Swiss Federal Institutes of Technology (ETH Domain) [ETH-Bereich; Domaine des Écoles polytechniques fédérales] (CH) with the aim of collaborating on scientific projects.

Reputation and ranking

ETH Zürich is ranked among the top universities in the world. Typically, popular rankings place the institution as the best university in continental Europe and ETH Zürich is consistently ranked among the top 1-5 universities in Europe, and among the top 3-10 best universities of the world.

Historically, ETH Zürich has achieved its reputation particularly in the fields of chemistry, mathematics and physics. There are 32 Nobel laureates who are associated with ETH Zürich, the most recent of whom is Richard F. Heck, awarded the Nobel Prize in chemistry in 2010. Albert Einstein is perhaps its most famous alumnus.

In 2018, the QS World University Rankings placed ETH Zürich at 7th overall in the world. In 2015, ETH Zürich was ranked 5th in the world in Engineering, Science and Technology, just behind the Massachusetts Institute of Technology(US), Stanford University(US) and University of Cambridge(UK). In 2015, ETH Zürich also ranked 6th in the world in Natural Sciences, and in 2016 ranked 1st in the world for Earth & Marine Sciences for the second consecutive year.

In 2016, Times Higher Education WorldUniversity Rankings ranked ETH Zürich 9th overall in the world and 8th in the world in the field of Engineering & Technology, just behind the Massachusetts Institute of Technology(US), Stanford University(US), California Institute of Technology(US), Princeton University(US), University of Cambridge(UK), Imperial College London(UK) and University of Oxford(UK).

In a comparison of Swiss universities by swissUP Ranking and in rankings published by CHE comparing the universities of German-speaking countries, ETH Zürich traditionally is ranked first in natural sciences, computer science and engineering sciences.

In the survey CHE ExcellenceRanking on the quality of Western European graduate school programs in the fields of biology, chemistry, physics and mathematics, ETH Zürich was assessed as one of the three institutions to have excellent programs in all the considered fields, the other two being Imperial College London(UK) and the University of Cambridge(UK), respectively.

Universität Wien Campus

University of Vienna [Universität Wien](AT) is a public university located in Vienna, Austria.It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world. With its long and rich history, the University of Vienna has developed into one of the largest universities in Europe, and also one of the most renowned, especially in the Humanities. It is associated with 21 Nobel prize winners and has been the academic home to many scholars of historical as well as of academic importance.

From the Middle Ages to the Enlightenment

The University was founded on 12 March 1365 by Rudolf IV, Duke of Austria, and his two brothers, Dukes Albert III and Leopold III, hence the additional name “Alma Mater Rudolphina”. After the Charles University in Prague [Univerzita Karlova](CZ) and Jagiellonian University [Uniwersytet Jagielloński](PL), the University of Vienna is the third oldest university in Central Europe and the oldest university in the contemporary German-speaking world; it remains a question of definition as the Charles University in Prague [Univerzita Karlova](CZ) was German-speaking when founded, too.

The University of Vienna was modelled after the University of Paris [Université de Paris](FR). However, Pope Urban V did not ratify the deed of foundation that had been sanctioned by Rudolf IV, specifically in relation to the department of theology. This was presumably due to pressure exerted by Charles IV, Holy Roman Emperor, who wished to avoid competition for the Charles University in Prague. Approval was finally received from the Pope in 1384 and the University of Vienna was granted the status of a full university, including the Faculty of Catholic Theology. The first university building opened in 1385. It grew into the biggest university of the Holy Roman Empire, and during the advent of Humanism in the mid-15th century was home to more than 6,000 students.

In its early years, the university had a partly hierarchical, partly cooperative structure, in which the Rector was at the top, while the students had little say and were settled at the bottom. The Magister and Doctors constituted the four faculties and elected the academic officials from amidst their ranks. The students, but also all other Supposita (university members), were divided into four Academic Nations. Their elected board members, mostly graduates themselves, had the right to elect the Rector. He presided over the Consistory which included procurators of each of the nations and the faculty deans, as well as over the University Assembly, in which all university teachers participated. Complaints or appeals against decisions of faculty by the students had to be brought forward by a Magister or Doctor.

Being considered a Papal Institution, the university suffered quite a setback during the Reformation. In addition, the first Siege of Vienna by Ottoman forces had devastating effects on the city, leading to a sharp decline, with only 30 students enrolled at the lowest point. For King Ferdinand I, this meant that the university should be tied to the church to an even stronger degree, and in 1551 he installed the Jesuit Order there. With the enacting of the Sanctio Pragmatica edict by emperor Ferdinand II in 1623, the Jesuits took over teaching at the theological and philosophical faculty, and thus the university became a stronghold of Catholicism for over 150 years. It was only in the Mid-18th century that Empress Maria Theresa forced the university back under control of the monarchy. Her successor Joseph II helped in the further reform of the university, allowing both Protestants and Jews to enroll as well as introducing German as the compulsory language of instruction.

From the 19th Century Onwards

Big changes were instituted in the wake of the Revolution in 1848, with the Philosophical Faculty being upgraded into equal status as Theology, Law and Medicine. Led by the reforms of Leopold, Count von Thun und Hohenstein, the university was able to achieve a larger degree of academic freedom. The current main building on the Ringstraße was built between 1877 and 1884 by Heinrich von Ferstel. The previous main building was located close to the Stuben Gate (Stubentor) on Iganz Seipel Square, current home of the old University Church (Universitätskirche) and the Austrian Academy of Sciences [Österreichische Akademie der Wissenschaften(AT). Women were admitted as full students from 1897, although their studies were limited to Philosophy. The remaining departments gradually followed suit, although with considerable delay: Medicine in 1900, Law in 1919, Protestant Theology in 1923 and finally Roman Catholic Theology in 1946. Ten years after the admission of the first female students, Elise Richter became the first woman to receive habilitation, becoming professor of Romance Languages in 1907; she was also the first female distinguished professor.

In the late 1920s, the university was in steady turmoil because of anti-democratic and anti-Semitic activity by parts of the student body. Professor Moritz Schlick was killed by a former student while ascending the steps of the University for a class. His murderer was later released by the Nazi Regime. Following the Anschluss, the annexation of Austria into Greater Germany by the Nazi regime, in 1938 the University of Vienna was reformed under political aspects and a huge number of teachers and students were dismissed for political and “racial” reasons. In April 1945, the then 22-year-old Kurt Schubert, later acknowledged doyen of Judaic Studies at the University of Vienna, was permitted by the Soviet occupation forces to open the university again for teaching, which is why he is regarded as the unofficial first rector in the post-war period. On 25 April 1945, however, the constitutional lawyer Ludwig Adamovich senior was elected as official rector of the University of Vienna. A large degree of participation by students and university staff was realized in 1975, however the University Reforms of 1993 and 2002 largely re-established the professors as the main decision makers. However, also as part of the last reform, the university after more than 250 years being largely under governmental control, finally regained its full legal capacity. The number of faculties and centers was increased to 18, and the whole of the medical faculty separated into the new Medical University of Vienna [Medizinische Universität Wien](AT).