Domain Patterns in the Microwave-Induced Zero-Resistance State

TL;DR

This paper investigates the domain structures and their effects in the microwave-induced zero-resistance state in GaAs 2D electron systems, focusing on how boundaries and disorder influence domain arrangements and conductance.

Contribution

It introduces a simple model with a Lyapunov functional to analyze domain patterns and the impact of boundaries and disorder on the zero-resistance state.

Findings

Domain arrangements are influenced by sample boundaries and disorder.

Domain-wall localization affects macroscopic conductance.

The model provides insights into the microscopic origins of the zero-resistance phenomenon.

Abstract

It has been proposed that the microwave-induced ``zero-resistance'' phenomenon, observed in a GaAs two-dimensional electron system at low temperatures in moderate magnetic fields, results from a state with multiple domains, in which a large local electric field $\bE(\br)$ is oriented in different directions. We explore here the questions of what may determine the domain arrangement in a given sample, what do the domains look like in representative cases, and what may be the consequences of domain-wall localization on the macroscopic dc conductance. We consider both effects of sample boundaries and effects of disorder, in a simple model, which has a constant Hall conductivity, and is characterized by a Lyapunov functional.