RQMP Research Seminar

Superconductivity in ultra-quantum matter: Part I

André-Marie Tremblay

Département de Physique Institut quantique & RQMP
Université de Sherbrooke

Copper-based superconductors have a single band near the Fermi surface, net spin 1/2 in the unit cell and effective interactions that are as large as kinetic energy. All of this makes quantum fluctuations very important. Their phase diagram is thus a challenge for the usual tools of solid state physics.

I will show how a perspective that takes into account both the localized and delocalized aspects of conduction electrons can explain, at least qualitatively, most experiments. More specifically, I will show that the work of several groups using cluster extensions of dynamical mean-field theory sheds light on phenomena characteristic of this class of systems: the pseudogap, the quantum-critical phenomena and d-wave superconductivity.

In another talk, Part II, I will argue that we know what leads to the largest transition temperature.