Asymmetric non-linear response of the IQHE

TL;DR

This paper investigates the asymmetric non-linear response of the integer quantum Hall effect, revealing rectification effects dependent on current direction and edge potential softness, supporting a screening theory of IQHE.

Contribution

It demonstrates how asymmetric edge potentials cause rectification in IQHE breakdown, providing experimental evidence for a screening theory.

Findings

Break-down current depends on edge potential softness.

Rectification occurs with asymmetric edge potentials.

Soft edges lead to more stable Hall-plateaus.

Abstract

An asymmetric break-down of the integer quantized Hall effect is investigated. This rectification effect is observed as a function of the current value and its direction in conjunction with an asymmetric lateral confinement potential defining the Hall-bar. Our electrostatic definition of the Hall-bar via Schottky-gates allows a systematic control of the steepness of the confinement potential at the edges of the Hall-bar. A softer edge (flatter confinement potential) results in more stable Hall-plateaus, i.e. a break-down at a larger current density. For one soft and one hard edge the break-down current depends on the current direction, resembling rectification. This non-linear magneto-transport effect confirms the predictions of an emerging screening theory of the IQHE.