News

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IQ retreat in Jouvence

January 2024

Some members of the Taillefer group attended the IQ retreat that happened in Jouvence (5th to the 6th of February). They also went on a long walk on the beautiful snowy trails!


Some Taillefer group members also made a small movie for their booth.

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Phonons become chiral from impurity scattering in the antiferromagnetic phase of Sr2IrO4

January 2024

The phonon Hall effect is a transverse temperature difference of phononic origin that is generated when an external magnetic field is applied. This phenomenon is yet to be understood. It has been observed in a growing number of insulators in which phonons have been found to be the main heat carriers. How are phonons, neutral excitations without any charge or spin, influenced by an external magnetic field? From a collaboration between Quebec and France, Amir and his collaborators have been trying to answer this question by studying the insulator Sr2IrO4. They found that impurities seem to play an important role!


Ataei et al., Nature Physics (2024)

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Graduation ceremony 2023

September 2023

Congratulations to Étienne, who obtained his doctorate after defending a thesis on thermal transport in the Kitaev quantum spin liquid spin candidate α-RuCl3!


Link to Étienne's thesis manuscript.

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Think Small: How quantum will change the world

June 2023

Researchers in CIFAR’s Quantum Materials and Quantum Information Science programs are advancing quantum technologies that will revolutionize computing, electrical grids, transportation networks, and more.


Full article on the CIFAR website.

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Electrons with Planckian scattering obey standard orbital motion in a magnetic field

December 2022

In strange metals, electrons undergo Planckian dissipation. The temperature dependence of this strong scattering is anomalous (linear rather than quadratic resistivity). The Taillefer group has shown that the magnetic field dependence of this scattering is normal.


Electrons with Planckian scattering obey standard orbital motion in a magnetic field
Ataei et al., Nat. Phys. 18, 1420-1424 (2022).


Electrons with Planckian scattering in strange metals follow standard rules of orbital motion in a magnet
I. Fadelli, Phys.org


Influence of high magnetic fields on electrons undergoing Planckian dissipation
EMFL News, 4 (2022)


Percer les mystères des matériaux quantiques avec les champs magnétiques les plus intenses
H. Vincelette, IQ News (2023)

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Quantum technology: a new France-Canada network

November 2022

An international network in quantum science and technology, set in motion by the CNRS, will officially be launched as of January 1, 2023. 16 French and Canadian universities will be part of this network, including the University of Sherbrooke, and Louis Taillefer will be a member of the executive committee.


Full article on the CNRS website.

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Cifar Quantum Materials Program Meeting

May 2022

A few member of the Taillefer group attended the in-person Toronto 2022 Cifar Meeting. They had a great experience with lots of interresting discussion!


This program is working towards bringing on the Quantum Age. It explores the fundamental science behind quantum matter — the resource for the quantum technologies that will define the 21st century. These technologies could include room-temperature superconductors that would carry electricity without any loss and revolutionize power transmission. Or quantum tech could include the quantum computer that would exploit the entanglement of multiple electrons, resulting in a powerful way to manipulate information. And there are the quantum materials innovations we cannot yet imagine.

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New publication on thermal transport in α-RuCl3

April 2022

Quantum spin liquids are materials that have the potential, in theory, to host novel kinds of particles or excitations, such as spinons or Majorana fermions. The challenge for experimentalists is to conclusively detect these. Some of the predicted excitations are mobile and thus detectable with thermal transport measurements. Using thermal Hall conductivity—a transverse thermal conductivity generated by a magnetic field—we shed new light on mobile carriers of heat in one spin liquid candidate, α-RuCl3.


Evidence of a Phonon Hall Effect in the Kitaev Spin Liquid Candidate α-RuCl3
Lefrançois, Grissonnanche et al., PRX 12, (2022).

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First publication of the year 2022!

February 2022

High-temperature superconductors have the potential to revolutionize the way we transport and store energy, but first, we must unravel the way electrons interact with each other within these unique quantum materials. In the copper-oxide materials called cuprates, electrons enter one of two unusual electronic phases of matter before they pair to become superconducting: the “strange metal” and “pseudogap” phases. The nature of these two phases is not fully understood and studying them can tell us how electrons collectively organize themselves to produce superconductivity. We shed new light on both phases by measuring the Seebeck effect: the electrical response of a cuprate to a temperature gradient.


Seebeck Coefficient in a Cuprate Superconductor: Particle-Hole Asymmetry in the Strange Metal Phase and Fermi Surface Transformation in the Pseudogap Phase
Gourgout, Grissonnanche et al., PRX 12, 011037 (2022).

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Planckian limit: a discovery by the group among the 10 discoveries of the year 2021 by Québec Science

January 2022

As tradition dictates, each year, the magazine Québec Science highlights 10 discoveries that have stood out over the past year. The study by the Taillefer group, led by our former postdoctoral fellow Gaël Grissonnanche, on linear resistivity in strange metals and the Planckian limit is one of the finalists! Congratulations to the whole team.


Linear-in temperature resistivity from an isotropic Planckian scattering rate
Grissonnanche et al., Nature 595, 667 (2021).

Une limite de vitesse au coeur de la matière
Joël Leblanc, Québec Science

Deux découvertes de l'UdeS en lice au palmarès Québec Science
Sabrine Laboie, La tribune

Deux percées de l'université de Sherbrooke parmi les découvertes de l'année les plus remarquables
Valérie Millette, Institut Quantique

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Writing retreat!

November 2021

The members of the Taillefer group have just returned from a very productive week of writing at Jouvence! A good time to write, discuss and refocus. Several publications to come ...

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Colloque LIA-CNRS-Université de Sherbrooke 2021

September 2021

The sixth meeting of the Franco-Canadian International Associated Laboratory (LIA) "Quantum circuits and materials" took place at Ax-les-Thermes in France from September 28 to October 1st, 2021. The members of the Taillefer group were present in large numbers! This symposium covered superconducting circuits and hybrid quantum devices on the one hand, and correlated systems and unconventional superconductivity on the other.

Building on the collaboration between French researchers and researchers from the Department of Physics of the University of Sherbrooke for several decades, the International Associated Laboratory (LIA) - Laboratory on Quantum Circuits and Materials (LIA LCMQ) was created in 2016 to strengthen research collaborations within the France-Canada axis.


Webpage of LIA
lia-crns-udes

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Planckian limit and linear resistivity : new discovery!

July 2021

In collaboration with an American team, Prof. Taillefer's group has just measured precisely what is mysteriously called the "Planckian limit" in strange metals (Nature 595, 667 (2021)). This limit, which seems to be determined by quantum mechanics and Planck's constant, imposes that when electrons collide at an extreme rate within matter, each electron has at least the Planckian time to rest before the next collision. The reasons for the Planckian limit remain a mystery.


Linear-in temperature resistivity from an isotropic Planckian scattering rate
Grissonnanche et al., Nature 595, 667 (2021).

A new quantum limit for electrons
Jon Farrow, CIFAR

A team from Institut quantique has identified what appears to be a new quantum limit for electrons
Communication IQ, Institut Quantique

Chaotic electrons heed ‘limit’ in strange metals
David Nutt, Cornell Chronicle

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Pr Louis Taillefer membre de la Royal Society of London

May 2021

Louis is now among the new members of the Royal Society of London. It is one of the oldest academic society in the world. Congratulations Louis for this honor!


A major scientific honor for Professor Louis Taillefer
Johanne Leroux, Institut Quantique

Entrevue avec Louis Taillefer, professeur au département de physique de l'UdeS
Stéphan Bureau, Bien entendu, Radio-Canada

Physicist Professor Louis Taillefer made Fellow of the Royal Society
Corpus Christi College, University of Cambridge

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Superconductors : The Magic and the Mystery

October 2020

Louis was invited to give a public virtual lecture on superconductivity.


Simons Foundation Lectures are free public colloquia related to basic science and mathematics. These high-level talks are intended for professors, students, postdocs and business professionals, but interested people from the metropolitan area are welcome as well.

Simons Foundation Lectures

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Weyl semimetal: 2 publications in PRB

September 2020

The collaboration between the Taillefer group and the team of Professor James Analytis (UC Berkeley) as well as Professor Jeffrey Quilliam (University of Sherbrooke) led to the publication of two papers on TaAs, a Weyl semi-metal, in PRB.


Field-angle dependence of sound velocity in the Weyl semimetal TaAs
F. Laliberté et al., Phys. Rev. B 102, 125104 (2020).

Signatures of possible surface states in TaAs
N.L. Nair et al., Phys. Rev. B 102, 075402 (2020).

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New publication in Nature Physics

July 2020

Professor Taillefer's group continues to investigate the giant negative thermal Hall effect discovered last year in the pseudogap phase of superconducting cuprates (Nature 571, 376-380 (2019)). The team now reveals that this effect comes from the atomic vibrations of the material, the phonons. But how can it be that particles without an electric charge still manage to couple to the external magnetic field to generate a thermal Hall effect? Those responsible for the phenomenon have now been unmasked, but the origin of this mystery remains unsolved.


Chiral phonons in the pseudogap phase of cuprates
G. Grissonnanche et al., Nature Physics (2020).

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Reopening of the lab!

May 2020

Simon Fortier is preparing to reopen our two laboratories: cooling cryogenic systems, repair and maintenance of pumps as well as implementing security measures. This is the first step towards restarting research!

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COVID-19 : T-wave group working from home !

Mars 2020

We hope everyone is safe in these uncertain times. In the meantime, we are lucky to work from home and we keep smiling. . We will be back soon :) .

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New article in PRX

December 2019

Using thermal conductivity measurements, we investigated the issue of potential mobile spin excitations in a promising quantum spin liquid candidate and found no evidence that spinons contribute to heat transport. Despite measuring eight high-quality crystals, we were not able to reproduce the findings of a previous report on the same material that had found the opposite result.


Thermal conductivity of the quantum spin liquid candidate EtMe3Sb[Pd(dmit)2]2: No evidence of mobile gapless excitations
P. Bourgeois-Hope et al, PRX 9, 041051 (2019).

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Relève étoile Louis-Berlinguet Prize

October 2019

Congratulations to Gaël Grissonnanche, a post-doctoral student in Taillefer's group, for winning the Relève étoile Louis-Berlinguet. This award, granted but the Fonds de recherche- Nature et technologies (Québec), recognizes the excellence of research conducted by university-level students. Gaël received this award following her article Giant thermal Hall conductivity in the pseudogap phase of cuprate superconductors published in Nature in July 2019.


Giant thermal Hall conductivity in the pseudogap phase of cuprate superconductors
G. Grissonnanche et al. Nature 571, 376-380 (2019).

Giant thermal Hall effect reveals novel particles in high-temperature superconductors
Nicolas Doiron-Leyraud, Institut Quantique

Crafting new particles in the core of superconducting materials
Hugues Vincelette, Institut Quantique

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Workshop LIA - CNRS - Université de Sherbrooke

October 2019

The international colloquium on quantum circuits and materials was held in Jouvence from October 2nd to 4th. All of the Taillefer group attended to discuss the latest advances in the field of quantum materials with our French collaborators.
Taking its roots in the decade-long collaborations between French researchers and members of the Physics Department of the Université de Sherbrooke, the LIA (International Associated Laboratory) on quantum circuits and materials was created in 2016 to strengthen research collaborations across the France-Canada axis.


Website
Laboratoire de Circuits et Matériaux Quantiques

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Graduation ceremony 2019

September 2019

This year, four students of the Taillefer group were invited to the Université de Sherbrooke's graduation ceremony, held on September 21st. Amirreza Ataei, Marie-Eve Boulanger and Maude Lizaire received their Master's diplomas, whilst Anaëlle Legros was awarded her PhD diploma. Congratulations to all for your achievements!


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New Article in Nature!

July 2019

An experiment led by the Taillefer group has now found something entirely new and unexpected about the pseudogap phase, this mysterious electronic phase of matter that coexists with superconductivity and is considered one of the great enigmas in physics today: it harbors exotic excitations that produce a negative thermal Hall effect.


Giant thermal Hall conductivity in the pseudogap phase of cuprate superconductors
G. Grissonnanche et al. Nature 571, 376-380 (2019).

Giant thermal Hall effect reveals novel particles in high-temperature superconductors
Nicolas Doiron-Leyraud, Institut Quantique

Crafting new particles in the core of superconducting materials
Hugues Vincelette, Institut Quantique

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Prix d'excellence FRQNT 2019

June 2019

Louis Taillefer, together with Pr Yoshua Bengio (Department of Computer Science and Operations Research of the Université de Montréal) received the 2019 Prix d'excellence FRQNT. The Prix d'excellence FRQNT, in the amount of $10,000, recognizes the outstanding contributions of university or college researchers in the areas of natural sciences, mathematics and engineering, their international reputation and the benefits of their research for Québec.


Yoshua Bengio and Louis Taillefer, winners of the 2019 Prix d'excellence FRQNT
FRQNT, Fonds de recherche nature et technologies

Le professeur Louis Taillefer honoré par le Fonds de recherche du Québec - nature et technologies
Rosalie Cyr, Institut Quantique

CIFAR leaders Yoshua Bengio and Louis Taillefer honoured with Quebec science prize
Jon Farrow, CIFAR

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Relève étoile Louis-Berlinguet Prize

May 2019

Congratulations to Anaëlle Legros, a former doctoral student in the Taillefer group, for winning the Relève étoile Louis-Berlinguet. This award, granted but the Fonds de recherche- Nature et technologies (Québec), recognizes the excellence of research conducted by university-level students. Anaëlle received this award following her article Universal T-linear resistivity and Planckian dissipation in overdoped cuprates published in Nature Physics in November 2018.


Universal T-linear resistivity and Planckian dissipation in overdoped cuprates
A. Legros et al, Nature Physics 15, 142 (2019).

Universal Quantum Phenomenon Found in Strange Metals
Nathalie Wolchver, Quanta Magazine

IQ Scientits unravel yet another mystery of high-temperature superconductors
Nicolas Doiron-Leyraud, Institut Quantique

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Gordon Research Conference on Superconductivity

May 2019

Members of the Taillefer group at the top of Glacier 3000, Switzerland, during the Gordon Research Conference (GRC) on Superconductivity. GRC is a non-profit organization dedicated to building communities that go beyond the boundaries of science. This conference brought together professors, postdocs, scientists, scientific publishers and students to discuss the latest research on superconductivity. Gaël Grissonnanche, post-doc in the group, was invited to share his results in the form of an oral presentation at the student seminar.

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Quantum Material Summer School

April 2019

The Quantum Materials Summer School was held at the Stewart Blusson Quantum Matter Institute in Vancouver from April 8 - 10, 2019. Marie-Eve, Étienne and Gaël were able to learn more about 2D materials and van der Waals heterostructures.

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APS March Meeting

March 2019

Étienne Lefrançois, Gaël Grissonnanche, Bastien Loret and Adrien Gourgout went to the 2019 March Meeting organized by the American Physical Society. This event, which brings together more than 11,000 physicists from around the globe, offers a unique opportunity to discover and present innovative research from universities and leading laboratories.

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New article in Nature !

February 2019

We recently first putted in evidence, by using high field specific heat measurements, the quantum criticality nature of the pseudogap critical point, called p*, in the cuprate superconductors. Two signatures are remarkable and are the archetypes of a quantum critical point: a logarithmic temperature dependence of the electronic specific at the critical point as the temperature goes to zero, and, at low temperature, an effective mass enhancement by crossing the critical point. This discovery supports the paradigm of the pseudogap fluctuations like a glue for the Cooper pairs mechanism.

Thermodynamic signatures of quantum criticality in cuprate superconductors
B. Michon et al, Nature 567,218-222 (2019).

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Winter school at University of Maryland

January 2019

Marie-Eve Boulanger, Étienne Lefrançois and Adrien Gourgout, three members of the group, went to the Fundamentals of Quantum Materials Winter School. They developed their knowledge in synthesis, characterization and electronic modeling of quantum materials.


The photo gallery can be found here!

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New article published in Nature Physics

Novembre 2018

Experiments suggest that exotic superconducting materials share a "strange metal" state characterized by a quantum speed limit that somehow acts as a fundamental organizing principale


Universal T-linear resistivity and Planckian dissipation in overdoped cuprates
A. Legros et al, Nature Physics 15, 142 (2019).

Universal Quantum Phenomenon Found in Strange Metals
Nathalie Wolchver, Quanta Magazine

IQ Scientits unravel yet another mystery of high-temperature superconductors
Nicolas Doiron-Leyraud, Institut Quantique

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Kamerlingh Onnes Prize 2018

August 2018

On August 21, 2018, Louis Taillefer receive the Karmelingh Onnes prize for his important research of transport measurement in heavy fermions and curates superconductors under high magnetic fields.


Pr Louis Taillefer reçoit une nouvelle accolade internationale
Faculté des sciences, Université de Sherbrooke

Louis Taillefer wins Kamerlingh Onnes prize for superconductivity research
CIFAR, Canadian Institute for Quantum Research

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Simon Memorial Prize

March 2017

Louis Taillefer is the first Canadian to receive the prize since it was established in 1957. Every three years, the Institute of Physics (IOP) gives this international prize in recognition of honorable work in low temperature physics either in theoretical and experimental physics..


CIFAR’s quantum physicist Louis Taillefer first Canadian to win Simon Prizen
CIFAR, Canadian Institute for Quantum Research

Louis Taillefer : premier Canadien à recevoir le prix Simon Memorial
Faculté des sciences, Université de Sherbrooke