Competing charge density waves probed by non-linear transport and noise in the second and third Landau levels

TL;DR

This study investigates charge density waves in the second and third Landau levels using non-linear transport and noise measurements, revealing phase competition and bulk properties in quantum Hall states.

Contribution

It introduces a Corbino geometry approach to probe bulk CDWs and uncovers their sliding behavior and phase competition in Landau levels.

Findings

Detection of narrow band noise indicating sliding CDWs

Observation of phase competition between stripe, pinned CDW, and fractional quantum Hall states

Clear evidence of bulk properties without edge state contributions

Abstract

Charge density waves (CDW) in the second and third Landau levels (LL) are investigated by both non-linear electronic transport and noise. The use of a Corbino geometry ensures that only bulk properties are probed, with no contribution from edge states. Sliding transport of CDWs is revealed by narrow band noise in re-entrant quantum Hall states R2a and R2c of the second LL as well as in pinned CDWs of the third LL. Competition between various phases - stripe, pinned CDW or fractional quantum Hall liquid - in both LL are clearly revealed by combining noise data with maps of conductivity versus magnetic field and bias voltage.