Hall magnetocapacitance in two-dimensional electron systems

TL;DR

This study explores the magnetocapacitance behavior of two-dimensional electron systems across various frequencies and magnetic conditions, revealing a new response mechanism linked to Hall conductivity and sample boundaries.

Contribution

It reports a novel response mechanism in 2DES magnetocapacitance influenced by transverse conductivity and boundaries, extending understanding beyond Quantum Hall conditions.

Findings

Identified a resistive cutoff frequency related to longitudinal conductivity.

Discovered a new response mechanism controlled by Hall conductivity.

Observed effects at frequencies below edge magnetoplasma resonances.

Abstract

The magnetocapacitance of a two-dimensional electron system (2DES) is investigated experimentally, both under and away from Quantum Hall (QH) conditions, at frequencies between 1 kHz and 100 MHz. The nature of the capacitive signal in a bounded 2DES is determined by a resistive cut-off frequency 1/$\tau \propto \sigma_{xx}$, the longitudinal magnetoconductivity. A new response mechanism is reported for angular frequencies $\omega > 1/\tau$, which is controlled by the $\em transverse$ or Hall conductivity $\sigma_{xy}$ and the boundaries of the sample, even at frequencies far below those of the Edge Magnetoplasma resonances and away from the QH-conditions.