Analysis Seminar

Title: Magic angles and high Chern number flat band of a twisted multilayer graphene model
Speaker: Mengxuan Yang
Speaker Info: Berkeley
Brief Description:
Special Note:

n condensed matter physics, when two or more sheets of graphene are twisted by certain angles, a.k.a. magic angles, the resulting material becomes superconducting. The mathematics behind this is a blend of basic representation theory, Bloch-Floquet theory, Jacobi theta functions and holomorphic line bundles. In this talk, I will compare a chiral multilayer graphene (TMG) model with the chiral twisted bilayer graphene (TBG) model studied by Tarnopolsky--Kruchkov--Vishwanath and Becker--Embree--Wittsten--Zworski to show that magic angles of TMG are the same with magic angles of TBG. I will also present a band separation due to the interlayer tunneling by setting up a Grushin problem. Finally, I will present a construction of a holomorphic line bundle with Chern number $-n$. The high Chern number band attracts many attentions in physics for its role in both integer and fractional quantum Hall effect.
Date: Monday, May 22, 2023
Time: 4:10pm
Where: Lunt 105
Contact Person: Prof. Jared Wunsch
Contact email: jwunsch@math.northwestern.edu
Contact Phone: 847-491-5580
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