Spatially resolved breakdown in reentrant quantum Hall states

TL;DR

This study uses spatially-resolved measurements to reveal that breakdown in reentrant quantum Hall states propagates chirally from contacts, with the direction depending on the electron or hole nature of the state, shedding light on their microscopic behavior.

Contribution

It provides the first spatially-resolved visualization of the breakdown process in RIQH states, linking the phase boundary propagation to the electron or hole character of the state.

Findings

Breakdown propagates chirally from contacts.

Propagation direction depends on electron/hole character.

Breakdown involves a phase boundary between broken and unbroken regions.

Abstract

Reentrant integer quantum Hall (RIQH) states are believed to be correlated electron solid phases, though their microscopic description remains unclear. As bias current increases, longitudinal and Hall resistivities measured for these states exhibit multiple sharp breakdown transitions, a signature unique to RIQH states. We present spatially-resolved measurements of RIQH breakdown that indicate these breakdown signatures can be ascribed to a phase boundary between broken-down and unbroken regions, spreading chirally from source and drain contacts as a function of bias current and passing voltage probes one by one. The chiral sense of the spreading is not set by the chirality of the edge state itself, instead depending on electron- or hole-like character of the RIQH state.