SP Seminar @ICTP Stasi Seminar Rm - Tuesday 29 January 11am - S. PARAMESWARAN

[CM Section]

Joint ICTP/SISSA Statistical Physics Seminar

Tuesday 29 January at 11:00 a.m.
Luigi Stasi Seminar Room, First floor, Leonardo building

S. PARAMESWARAN (Oxford, U.K.)

Topology, Symmetry, and Anomalies: Investigating
Domain Wall Physics in Quantum Hall Nematic States

Abstract:
I will present  recent work on ferromagnetic quantum Hall
states that form on (111) surfaces of elemental Bismuth in
high magnetic fields. This unusual states of matter combine
the topological features of quantum Hall states with orientational
symmetry breaking characteristic of nematic order.
Recent scanning tunneling microscopy measurements have
directly visualized the spontaneous formation of boundary
modes between distinct nematic domains and investigated their
electronic structure [1].
I will demonstrate that these boundary modes belong to a new
class of `symmetry-protected’ Luttinger liquid that arise from the
interplay of symmetry-breaking with quantum Hall physics, and
that they provide a concrete realization of `anomaly inflow’ [2].
The analysis reveals strikingly different behavior of domain
wall transport at quantum Hall filling factor $\nu=1,2$, in striking
agreement with the STM results. I will explore implications of
these ideas for the global phase diagram of quantum Hall valley
nematics [3].

References:
1. M.T. Randeria, K. Agarwal, B. E. Feldman, H. Ding , Huiwen Ji3 ,
R. J. Cava , S. L. Sondhi , S. A. Parameswaran, A. Yazdani,
under review
2. K. Agarwal, M.T. Randeria, A. Yazdani, S.L. Sondhi,
S.A. Parameswaran, arXiv:1807.10293
3. S.A. Parameswaran and B.E. Feldman, arXiv:1809.09616