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Abhay Pasupathy: Recent progress in moiré materials
November 4, 2021 @ 10:00 am - 11:00 am
Meeting ID: 668 7999 5529
Speaker: Abhay Pasupathy, Columbia University
Abstract: I will discuss two recent sets of experiments from my group on moiré materials. In the first experiment, I will discuss transport experiments on twisted bilayers of the monolayer semiconductor WSe2 (Wang et al, Nature Materials 19, 861 (2020) and Ghiotto et al Nature 597, 345 (2021)). In these experiments, we see the presence of an insulating state at half filling of the lowest subband of this material driven by electron correlations. I will describe our recent efforts to understand transport properties of this material and the evidence that there exist a ring of quantum critical points in this system at the metal-insulator transitions driven by doping and electric field. Time permitting, I will then discuss scanning tunneling microscopy experiments on magic-angle twisted trilayer graphene where superconductivity has recently been observed. These imaging experiments show that the atomic and electronic structure of twisted trilayer graphene has a number of unique differences from its elder brother, twisted bilayer graphene. I will speculate on the importance of these differences for superconductivity in this material.
Bio: Abhay Pasupathy is a Professor of Physics at Columbia University (since 2009) and a group leader in the Condensed Matter Physics and Materials Science Department at Brookhaven National Laboratory (since 2019). His group uses scan probe microscopies and electron transport measurement to study emergent quantum phases in materials. Two-dimensional materials including exfoliated and thin-film grown materials are of particular interest.