[institut] [phys4phys] SCL online seminar: Louk Rademaker, Thursday, 14 April, 14:00

[Antun Balaz]

Dear colleagues,

You are cordially invited to the SCL online seminar of the Center for the Study of Complex Systems, which will be held on Thursday, 14 April 2022 at 14:00 on Zoom (link is given below). The talk entitled

Symmetry breaking and Chern insulators in twisted graphene structures

will be given by Dr. Louk Rademaker (Department of Theoretical Physics, University of Geneva, Switzerland). Abstract of the talk:

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, we will show that many of the observed interacting phenomena can be explained in terms of breaking of spin/valley symmetry. To do so, we will first describe how flat bands in tBG can be directly observed using ARPES [1]. An effective description of the flat bands is hampered by band renormalization due to charge transfer [2] and band topology. The combination of interactions and topology naturally leads to spin/valley symmetry breaking with a quantum anomalous Hall effect in tMBG [3]. In tBG in large magnetic fields, similar spin/valley symmetry breaking creates a series of Chern insulator states [4]. We will conclude with a brief discussion of the possibility of genuine strong correlations in Moiré structures.

[1] S. Lisi, X. Lu, T. Benschop, et al., Nature Phys. 17, 189 (2021).
[2] L. Rademaker, D. A. Abanin, P. Mellado, Phys. Rev. B 100, 205114 (2019).
[3] L. Rademaker, I. V. Protopopov, D. A. Abanin, Phys. Rev. Research 2, 033150 (2020).
[4] Y. Saito, J. Ge, L. Rademaker, et al., Nat. Phys. 17, 478 (2021).

*********************************************
Time: Apr 14, 2022 14:00 Belgrade
https://us02web.zoom.us/j/89712694555?pwd=VElLcVhWUHpLVTFpRkdEdUpPUUdVQT09

Meeting ID: 897 1269 4555
Passcode: 580212
*********************************************

Best regards,
Antun Balaž

-----
Dr. Antun Balaž
Research Professor

http://www.scl.rs/antun
Phone: +381 11 3713152
Fax: +381 11 3162190

Scientific Computing Laboratory
Center for the Study of Complex Systems

Institute of Physics Belgrade
National Institute of the Republic of Serbia
Pregrevica 118, 11080 Belgrade, Serbia
-----