PhD Defenses

PHYSICS PHD DISSERTATION DEFENSE: Chao Wang

Date

Tue November 2nd 2021, 9:30am

Ph.D. Candidate: Chao Wang

Research Advisor: Prof. Steven Kivelson

Date: Tuesday, Nov 2, 2021
Time: 9:30am-12:00pm PDT

Zoom Link: https://stanford.zoom.us/j/91483845529

Zoom Password: email nickswan [at] stanford.edu (nickswan[at]stanford[dot]edu) before 12pm on Nov 1 for password.

Title: Nematic Antiferromagnetism and Deconfined Criticality from Interacting Electrons and Phonons

Abstract: Systems with strong electron-phonon couplings typically exhibit various forms of charge order, while strong electron-electron interactions lead to magnetism. We use determinant quantum Monte Carlo (DQMC) calculations to solve a model on a square lattice with a caricature of these interactions. In the limit where electron-electron interactions dominate it has antiferromagnetic (AF) order, while where electron-phonon coupling dominates there is columnar valence-bond solid (VBS) order. We find a novel intervening phase that hosts coexisting nematic and antiferromagnetic orders. We have also found evidence of a Landau-forbidden continuous quantum phase transition with an emergent O(4) symmetry between the VBS and the nematic antiferromagnetic phases.