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.
We recently revealed for the first time, by using high field specific heat measurements, the quantum critical nature of the pseudogap in the cuprate superconductors. Two signatures that are the archetypes of a quantum critical point were observed: a logarithmic temperature dependence of the electronic specific heat as the temperature goes to zero and an effective mass divergence at the critical point. This discovery supports the paradigm of the pseudogap fluctuations being involved in the Cooper pairs’ mechanism.
Thermodynamic signatures of quantum criticality in cuprate superconductors
B. Michon et al, Nature 567,218-222 (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.
Strong interactions between electrons is an inexhaustible source of intriguing collective properties. The quantum materials we study include unconventional superconductors, spin liquids, topological insulators and Weyl semimetals, among others. Our experimental approach consists of measuring the electric, thermal and thermoelectric transport properties of these materials under different conditions of temperature, magnetic field and pressure. These measurements allow us to explore the behaviour of electrons and to describe the underlying interactions.
Unconventional superconductors, spin liquids, topological insulators, Weyl semimetals.
Property of a material that allows it to transport an electric current with zero resistance and to expel a magnetic field.
Electric resistivity, thermal conductivity, Hall effect, Seebeck effect, Nernst effect, Righi-Leduc effect.
Two dilution fridges allow us to reach temperatures as low as a few dozen millikelvins.
Superconducting coils give us access to magnetic fields up to 20 T.
Our pressure cells can apply up to 2 GPa, the pressure of roughly 20 000 atmospheres.
Photo : UdeS - Martin Blache
Département de Physique
Université de Sherbrooke
2500 boul. Université, Sherbrooke (Québec)
Canada J1K 2R1