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  • richardmitnick 12:17 pm on May 16, 2022 Permalink | Reply
    Tags: "Unusual quantum state of matter observed for the first time at UdeM", , “Quantum spin liquid” state, , In quantum physics spin is an internal property of electrons linked to their rotation. It is spin that gives the material in a magnet its magnetic properties., In quantum spin liquids the electrons are positioned in a triangular lattice and form a “ménage à trois” characterized by intense turbulence that interferes with their order., Magnetism, , The University of Montréal [Université de Montréal] (CA)   

    From The University of Montréal [Université de Montréal] (CA) : “Unusual quantum state of matter observed for the first time at UdeM” 

    From The University of Montréal [Université de Montréal] (CA)

    05/09/2022
    Martin LaSalle

    1
    Physicist Andrea Bianchi has observed the “quantum spin liquid” state in a magnetic material created in his lab.

    It’s not every day that someone comes across a new state of matter in quantum physics, the scientific field devoted to describing the behaviour of atomic and subatomic particles in order to elucidate their properties.

    Yet this is exactly what an international team of researchers that includes Andrea Bianchi, University of Montreal physics professor and researcher at the Regroupement québécois sur les matériaux de pointe, and his students Avner Fitterman and Jérémi Dudemaine has done.

    In a recent article published in the scientific journal Physical Review X, the researchers document a “quantum spin liquid ground state” in a magnetic material created in Bianchi’s lab: Ce2Zr2O7, a compound composed of cerium, zirconium and oxygen.

    Like a liquid locked inside an extremely cold solid.

    In quantum physics, spin is an internal property of electrons linked to their rotation. It is spin that gives the material in a magnet its magnetic properties.

    In some materials, spin results in a disorganized structure similar to that of molecules in a liquid, hence the expression “spin liquid.”

    In general, a material becomes more disorganized as its temperature rises. This is the case, for example, when water turns into steam. But the principal characteristic of spin liquids is that they remain disorganized even when cooled to as low as absolute zero (–273°C).

    Spin liquids remain disorganized because the direction of spin continues to fluctuate as the material is cooled instead of stabilizing in a solid state, as it does in a conventional magnet, in which all the spins are aligned.

    The art of “frustrating” electrons

    Imagine an electron as a tiny compass that points either up or down. In conventional magnets, the electron spins are all oriented in the same direction, up or down, creating what is known as a “ferromagnetic phase.” This is what keeps photos and notes pinned to your fridge.

    But in quantum spin liquids, the electrons are positioned in a triangular lattice and form a “ménage à trois” characterized by intense turbulence that interferes with their order. The result is an entangled wave function and no magnetic order.

    “When a third electron is added, the electron spins cannot align because the two neighbouring electrons must always have opposing spins, creating what we call magnetic frustration,” Bianchi explained. “This generates excitations that maintain the disorder of spins and therefore the liquid state, even at very low temperatures.”

    So how did they add a third electron and cause such frustration?

    Creating a ménage à trois

    Enter the frustrated magnet Ce2Zr2O7 created by Bianchi in his lab. To his already long list of accomplishments in developing advanced materials like superconductors, we can now add “master of the art of frustrating magnets”!

    Ce2Zr2O7 is a cerium-based material with magnetic properties. “The existence of this compound was known,” said Bianchi. “Our breakthrough was creating it in a uniquely pure form. We used samples melted in an optical furnace to produce a near-perfect triangular arrangement of atoms and then checked the quantum state.”

    It was this near-perfect triangle that enabled Bianchi and his team at UdeM to create magnetic frustration in Ce2Zr2O7. Working with researchers at McMaster and Colorado State universities, Los Alamos National Laboratory and the Max Planck Institute for the Physics of Complex System in Dresden, Germany, they measured the compound’s magnetic diffusion.

    “Our measurements showed an overlapping particle function—therefore no Bragg peaks—a clear sign of the absence of classical magnetic order,” said Bianchi. “We also observed a distribution of spins with continuously fluctuating directions, which is characteristic of spin liquids and magnetic frustration. This indicates that the material we created behaves like a true spin liquid at low temperatures.”

    From dream to reality

    After corroborating these observations with computer simulations, the team concluded that they were indeed witnessing a never-before-seen quantum state.

    “Identifying a new quantum state of matter is a dream come true for every physicist,” said Bianchi. “Our material is revolutionary because we are the first to show it can indeed present as a spin liquid. This discovery could open the door to new approaches in designing quantum computers.”

    Frustrated magnets in a nutshell

    3

    Magnetism is a collective phenomenon in which the electrons in a material all spin in the same direction. An everyday example is the ferromagnet, which owes its magnetic properties to the alignment of spins. Neighbouring electrons can also spin in opposite directions. In this case, the spins still have well-defined directions but there is no magnetization. Frustrated magnets are frustrated because the neighbouring electrons try to orient their spins in opposing directions, and when they find themselves in a triangular lattice, they can no longer settle on a common, stable arrangement. The result: a frustrated magnet.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Université de Montréal is a French-language public research university in Montreal, Quebec, Canada. The university’s main campus is located on the northern slope of Mount Royal in the neighbourhoods of Outremont and Côte-des-Neiges. The institution comprises thirteen faculties, more than sixty departments and two affiliated schools: the Polytechnique Montréal (School of Engineering; formerly the École Polytechnique de Montréal) and HEC Montréal (School of Business). It offers more than 650 undergraduate programmes and graduate programmes, including 71 doctoral programmes.

    The university was founded as a satellite campus of the Université Laval in 1878. It became an independent institution after it was issued a papal charter in 1919 and a provincial charter in 1920. Université de Montréal moved from Montreal’s Quartier Latin to its present location at Mount Royal in 1942. It was made a secular institution with the passing of another provincial charter in 1967.

    The school is co-educational, and has 34,335 undergraduate and 11,925 post-graduate students (excluding affiliated schools). Alumni and former students reside across Canada and around the world, with notable alumni serving as government officials, academics, and business leaders.

    Research

    Université de Montréal is a member of the U15, a group that represents 15 Canadian research universities. The university includes 465 research units and departments. In 2018, Research Infosource ranked the university third in their list of top 50 research universities; with a sponsored research income (external sources of funding) of $536.238 million in 2017. In the same year, the university’s faculty averaged a sponsored research income of $271,000, while its graduates averaged a sponsored research income of $33,900.

    Université de Montréal research performance has been noted in several bibliometric university rankings, which uses citation analysis to evaluate the impact a university has on academic publications. In 2019, The Performance Ranking of Scientific Papers for World Universities ranked the university 104th in the world, and fifth in Canada. The University Ranking by Academic Performance 2018–19 rankings placed the university 99th in the world, and fifth in Canada.

    Since 2017, Université de Montréal has partnered with the McGill University (CA) on Mila (research institute), a community of professors, students, industrial partners and startups working in AI, with over 500 researchers making the institute the world’s largest academic research center in deep learning. The institute was originally founded in 1993 by Professor Yoshua Bengio.

     
  • richardmitnick 5:44 pm on January 12, 2022 Permalink | Reply
    Tags: "Chemists use DNA to build the world’s tiniest antenna", , , , , , DNA-based fluorescent nanoantenna, , , The University of Montréal [Université de Montréal] (CA)   

    From The University of Montréal [Université de Montréal] (CA) : “Chemists use DNA to build the world’s tiniest antenna” 

    From The University of Montréal [Université de Montréal] (CA)

    01/10/2022
    Salle De Presse

    1
    Developed at Université de Montréal, the easy-to-use device promises to help scientists better understand natural and human-designed nanotechnologies – and identify new drugs.

    Researchers at Université de Montréal have created a nanoantenna to monitor the motions of proteins.

    Reported this week in Nature Methods, the device is a new method to monitor the structural change of proteins over time – and may go a long way to helping scientists better understand natural and human-designed nanotechnologies.

    “The results are so exciting that we are currently working on setting up a start-up company to commercialize and make this nanoantenna available to most researchers and the pharmaceutical industry,” said UdeM chemistry professor Alexis Vallée-Bélisle, the study’s senior author.

    Works like a two-way radio

    Over 40 years ago, researchers invented the first DNA synthesizer to create molecules that encode genetic information. “In recent years, chemists have realized that DNA can also be employed to build a variety of nanostructures and nanomachines,” said Vallée-Belisle, who also holds the Canada Research Chair in Bioengineering and Bionanotechnology.

    “Inspired by the ‘Lego-like’ properties of DNA, with building blocks that are typically 20,000 times smaller than a human hair, we have created a DNA-based fluorescent nanoantenna, that can help characterize the function of proteins,” he said.

    “Like a two-way radio that can both receive and transmit radio waves, the fluorescent nanoantenna receives light in one colour, or wavelength, and depending on the protein movement it senses, then transmits light back in another colour, which we can detect.”

    One of the main innovations of these nanoantennae is that the receiver part of the antenna is also employed to sense the molecular surface of the protein studied via molecular interaction.

    One of the main advantages of using DNA to engineer these nanoantennas is that DNA chemistry is relatively simple and programmable,” said Scott Harroun, an UdeM doctoral student in chemistry and the study’s first author.

    “The DNA-based nanoantennas can be synthesized with different lengths and flexibilities to optimize their function,””he said. “One can easily attach a fluorescent molecule to the DNA, and then attach this fluorescent nanoantenna to a biological nanomachine, such as an enzyme.

    “By carefully tuning the nanoantenna design, we have created five nanometer-long antenna that produces a distinct signal when the protein is performing its biological function.”

    Fluorescent nanoantennas open many exciting avenues in biochemistry and nanotechnology, the scientists believe.

    “For example, we were able to detect, in real time and for the first time, the function of the enzyme alkaline phosphatase with a variety of biological molecules and drugs,” said Harroun. “This enzyme has been implicated in many diseases, including various cancers and intestinal inflammation.”

    Added Dominic Lauzon, a co-author of the study doing his PhD in chemistry at UdeM: “In addition to helping us understand how natural nanomachines function or malfunction, consequently leading to disease, this new method can also help chemists identify promising new drugs as well as guide nanoengineers to develop improved nanomachines.”

    One main advance enabled by these nanoantennas is also their ease-of-use, the scientists said.

    “Perhaps what we are most excited by is the realization that many labs around the world, equipped with a conventional spectrofluorometer, could readily employ these nanoantennas to study their favourite protein, such as to identify new drugs or to develop new nanotechnologies,” said Vallée-Bélisle.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Université de Montréal is a French-language public research university in Montreal, Quebec, Canada. The university’s main campus is located on the northern slope of Mount Royal in the neighbourhoods of Outremont and Côte-des-Neiges. The institution comprises thirteen faculties, more than sixty departments and two affiliated schools: the Polytechnique Montréal (School of Engineering; formerly the École Polytechnique de Montréal) and HEC Montréal (School of Business). It offers more than 650 undergraduate programmes and graduate programmes, including 71 doctoral programmes.

    The university was founded as a satellite campus of the Université Laval in 1878. It became an independent institution after it was issued a papal charter in 1919 and a provincial charter in 1920. Université de Montréal moved from Montreal’s Quartier Latin to its present location at Mount Royal in 1942. It was made a secular institution with the passing of another provincial charter in 1967.

    The school is co-educational, and has 34,335 undergraduate and 11,925 post-graduate students (excluding affiliated schools). Alumni and former students reside across Canada and around the world, with notable alumni serving as government officials, academics, and business leaders.

    Research

    Université de Montréal is a member of the U15, a group that represents 15 Canadian research universities. The university includes 465 research units and departments. In 2018, Research Infosource ranked the university third in their list of top 50 research universities; with a sponsored research income (external sources of funding) of $536.238 million in 2017. In the same year, the university’s faculty averaged a sponsored research income of $271,000, while its graduates averaged a sponsored research income of $33,900.

    Université de Montréal research performance has been noted in several bibliometric university rankings, which uses citation analysis to evaluate the impact a university has on academic publications. In 2019, The Performance Ranking of Scientific Papers for World Universities ranked the university 104th in the world, and fifth in Canada. The University Ranking by Academic Performance 2018–19 rankings placed the university 99th in the world, and fifth in Canada.

    Since 2017, Université de Montréal has partnered with the McGill University (CA) on Mila (research institute), a community of professors, students, industrial partners and startups working in AI, with over 500 researchers making the institute the world’s largest academic research center in deep learning. The institute was originally founded in 1993 by Professor Yoshua Bengio.

     
  • richardmitnick 9:52 am on September 24, 2021 Permalink | Reply
    Tags: "Astronomers Have Made an Unprecedented Detection of Clouds on a Far-Off Exoplanet", , , , , The University of Montréal [Université de Montréal] (CA), WASP-127b   

    From The University of Montréal [Université de Montréal] (CA) via Science Alert (US) : “Astronomers Have Made an Unprecedented Detection of Clouds on a Far-Off Exoplanet” 

    From The University of Montréal [Université de Montréal] (CA)

    via

    ScienceAlert

    Science Alert (US)

    24 SEPTEMBER 2021
    MICHELLE STARR

    1
    Artist’s impression of WASP-127b. (Gabriel Pérez, SMM (Institute of Astrophysics of the Canaries[Instituto de Astrofísica de Canarias] (ES))

    Using data from multiple telescopes, scientists have detected clouds on a gas giant exoplanet some 520 light-years from Earth. So detailed were the observations, they even discerned the altitude of the clouds and the structure of the upper atmosphere, with the greatest precision yet.

    It’s work that will help us better understand exoplanet atmospheres – and look for worlds that may have conditions hospitable to life, or biosignatures in their spectra. We’re also getting closer to making weather reports for distant alien worlds.

    The exoplanet in question is WASP-127b, discovered in 2016. It’s a hot and therefore puffy beast, orbiting so close to its star that its year is just 4.2 days. The exoplanet clocks in at 1.3 times the size of Jupiter, but only 0.16 times Jupiter’s mass.

    This means that its atmosphere is somewhat thin and tenuous – perfect for trying to analyze its contents based on the light that streams through it from the exoplanet’s host star.

    To do this, a team of researchers led by astronomer Romain Allart of the Université de Montréal in Canada combined infrared data from the space-based Hubble Space Telescope, and optical data from the ESPRESSO instrument on the ground-based Very Large Telescope, to peer into different altitudes of WASP-127b’s atmosphere.

    “First, as found before in this type of planet, we detected the presence of sodium, but at a much lower altitude than we were expecting,” Allart said.

    “Second, there were strong water vapor signals in the infrared but none at all at visible wavelengths. This implies that water vapor at lower levels is being screened by clouds that are opaque at visible wavelengths but transparent in the infrared.”

    Figuring out the composition of exoplanetary atmospheres is a tricky thing to do. That’s because we can’t see most exoplanets directly; we infer their presence based on the effects they have on their host stars. One of these is dimming and brightening – when the exoplanet passes between us and the star, the light from the star dims, just a tiny bit.

    If it does this enough times, on a regular schedule, then that’s one of the telltale signs of an orbiting exoplanet. And we can use this information in other ways, too. When the starlight passes through the exoplanet’s atmosphere, wavelengths in the spectrum can be absorbed or by different elements. We call these signatures absorption lines, and we can decode them to see what’s in that atmosphere.

    2
    Wasp-127b compared to the Solar System. (David Ehrenreich/University of Geneva [Université de Genève](CH); Romain Allart/Université de Montréal)

    That’s what Allart and his team did, using high-resolution absorption data to narrow down the altitude of the clouds to a surprisingly low cloud layer with atmospheric pressure between 0.3 and 0.5 millibars.

    “We don’t yet know the composition of the clouds, except that they are not composed of water droplets like on Earth,” said Allart.

    “We are also puzzled about why the sodium is found in an unexpected place on this planet. Future studies will help us understand not only more about the atmospheric structure, but about WASP-127b, which is proving to be a fascinating place.”

    The team’s analysis also found some peculiar things about how WASP-127b orbits its host star. In the Solar System, where things are orderly, all the planets orbit in the direction of the Sun’s rotation, in a more-or-less flat plane around the Sun’s equator. This is because of the way the Solar System formed, from a disc of material swirling into the spinning baby Sun.

    WASP-127b orbits not just in the opposite direction of its star’s rotation, but at a very pronounced angle, almost around the star’s poles. The system is thought to be around 10 billion years old, which means something strange is definitely going on in that particular neighborhood.

    “Such alignment is unexpected for a hot Saturn in an old stellar system and might be caused by an unknown companion,” Allart said.

    “All these unique characteristics make WASP-127b a planet that will be very intensely studied in the future.”

    The research was published in Astronomy & Astrophysics, and presented at the 2021 Europlanet Science Congress.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Université de Montréal is a French-language public research university in Montreal, Quebec, Canada. The university’s main campus is located on the northern slope of Mount Royal in the neighbourhoods of Outremont and Côte-des-Neiges. The institution comprises thirteen faculties, more than sixty departments and two affiliated schools: the Polytechnique Montréal (School of Engineering; formerly the École Polytechnique de Montréal) and HEC Montréal (School of Business). It offers more than 650 undergraduate programmes and graduate programmes, including 71 doctoral programmes.

    The university was founded as a satellite campus of the Université Laval in 1878. It became an independent institution after it was issued a papal charter in 1919 and a provincial charter in 1920. Université de Montréal moved from Montreal’s Quartier Latin to its present location at Mount Royal in 1942. It was made a secular institution with the passing of another provincial charter in 1967.

    The school is co-educational, and has 34,335 undergraduate and 11,925 post-graduate students (excluding affiliated schools). Alumni and former students reside across Canada and around the world, with notable alumni serving as government officials, academics, and business leaders.

    Research

    Université de Montréal is a member of the U15, a group that represents 15 Canadian research universities. The university includes 465 research units and departments. In 2018, Research Infosource ranked the university third in their list of top 50 research universities; with a sponsored research income (external sources of funding) of $536.238 million in 2017. In the same year, the university’s faculty averaged a sponsored research income of $271,000, while its graduates averaged a sponsored research income of $33,900.

    Université de Montréal research performance has been noted in several bibliometric university rankings, which uses citation analysis to evaluate the impact a university has on academic publications. In 2019, The Performance Ranking of Scientific Papers for World Universities ranked the university 104th in the world, and fifth in Canada. The University Ranking by Academic Performance 2018–19 rankings placed the university 99th in the world, and fifth in Canada.

    Since 2017, Université de Montréal has partnered with the McGill University (CA) on Mila (research institute), a community of professors, students, industrial partners and startups working in AI, with over 500 researchers making the institute the world’s largest academic research center in deep learning. The institute was originally founded in 1993 by Professor Yoshua Bengio.

     
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