NEWS: The CQM Distinguished Lecture series has been established in the Fall of 2015 to bring to Stony Brook University the renown experts in the physics of quantum matter.
The lectures in this series will attract a broad audience of physicists from SBU and BNL,
and SBU graduate students.
December 2019 – April 2020
Dec
6
Fri
Title: Incommensurate transitions and twist disorder in microscopic models of twisted bilayer graphene
Abstract: Recent experiments in twisted bilayer graphene have set off a flurry of work due to the observation of purportedly correlated phases at the so-called “magic-angle.” However, the current models in the literature for magic-angle graphene suffer from two flaws: they assume commensurate twist angles and have great difficulty modeling the exact experimental setup where patches of different twist angles appear (“twist disorder”). We introduce and study a family of microscopic models that begins to address these concerns. In these models, the twist angle enters as a free parameter in real space. We can use this to simulate both incommensurate effects and disorder effects. We find that incommensuration leads to an Anderson-like delocalization transition in momentum space. The result is a small metallic phase at the “magic-angle” (that we speculate is unstable to correlated phases). We further study twist-disorder effects and find that while the minibandwidth is renormalized substantially, the Fermi velocity is not significantly altered.
Host: Jen Cano
Feb
7
Fri
Title: Microwave Nano-Imaging
Host: Mengkun
Mar
13
Fri
title: Ultrafast magnetism
host: Mengkun
Apr
3
Fri
title: Novel optical probe scanning method
host: Mengkun