Agenda

Symmetry breaking and Chern insulators in twisted graphene structures

Louk Rademaker (Department of Theoretical Physics, Université de Genève)

Mardi 28 septembre 2021 à 14h

Visio-conférence Zoom hybride depuis Salle Rémy Lemaire (salle K223)

Zoom link : https://univ-grenoble-alpes-fr.zoom.us/j/91808901596?pwd=UWZ2cml2N1VBOEZBenk0d3RJek9rdz09

Salle Rémy Lemaire : jauge limitée à 20 personnes

Abstract:

Twisted bilayer graphene (tBG) and variants like twisted monolayer-bilayer graphene (tMBG) were proposed to be a platform for strongly correlated physics akin to the cuprate family. However, I will show that many of the observed interacting phenomena can be explained in terms of breaking of spin/valley symmetry. This can lead to a quantum anomalous Hall effect in the absence of a field, as I will show for tMBG [1]. In large magnetic fields the same spin- valley symmetry breaking leads to a series of Chern insulator states [2]. Finally, I will briefly discuss the possibility of genuine strong correlated physics in Moiré structures.

[1] Rademaker, Protopopov, Abanin, Phys. Rev. Research, 2, 033150 (2020).
[2] Saito, Ge, Rademaker, Watanabe, Taniguchi, Abanin, Young, Nature Physics, 108, 12233 (2021)