Już 7 maja 2026 roku o godz. 12:30 w Audytorium Aleksandra Jabłońskiego dr hab. Magdalena Margańska-Łyżniak, prof. PWr (Wydział Podstawowych Problemów Techniki, Politechnika Wrocławska) wygłosi wykład pt. "What if: superconductivity from Coulomb repulsion in complex 2D materials".
Streszczenie:
The mystery of superconductors waited nearly 50 years for an explanation, provided in 1957 by Bardeen, Cooper and Schrieffer. They understood, among other facts, that in conventional superconductors the superconducting pairing relies on an effective attraction between electrons, mediated by the lattice vibrations.
Because scientists are not satisfied with one point of view only, soon afterwards (in 1965) Kohn and Luttinger proposed that in some materials overscreening of the Coulomb interaction could lead to effective attraction for some distance ranges.
Although this idea didn't work for elemental 3D superconductors (the estimated critical temperatures were way too low), it was revived with the advent of new 2D materials, such as few-layer graphene or metallic TMDCs.
In this talk I will explain how the multiorbital nature of the metallic band, the shape of the lattice and the reduced screening in two dimensions combine to screen the Coulomb interactions in a way that results in superconducting pairing, with the dominant gap of the exotic chiral p+ip symmetry. I will also discuss how such a gap would show up in the STM measurements, and how universal this mechanism is.
Organizatorem Kolokwium Czwartkowego jest Instytut Fizyki UMK w Toruniu.