Strange metals and flat bands: From topological heavy fermions to superconducting twisted-WSe2

  • Starts: 12:00 pm on Friday, November 1, 2024
  • Ends: 1:00 pm on Friday, November 1, 2024
Strong correlations and topology can mutually enrich each other. In this talk, I will illustrate both sides of this outstanding issue in two contexts. From one side, heavy fermions represent a canonical system for correlation physics. With appropriate symmetry, strong correlations lead to Weyl-Kondo semimetals [1] and, furthermore, strange metallicity gives rise to topological semimetals without quasiparticles [2,3]. From the other side, the very recent discovery that twisted-WSe2 superconducts has generated considerable excitement. I will argue that the moiré transition metal dichalcogenides represent a particularly transparent case where band topology yields new correlation physics. In an intermediate correlation regime, the band topology generates quantum fluctuations [4] that weaken an active flat band’s natural tendency for electronic order. The resulting competition enables a quantum critical regime from which superconductivity develops [5]. Some general implications of these exemplary cases will be discussed.
Location:
SCI 352
Speaker
Qimiao Si
Institution
Rice University
Host
Anders Sandvik