Transverse rectification in density-modulated two-dimensional electron gases

TL;DR

This paper reports on tunable transverse rectification in a density-modulated 2DEG, showing a quadratic dependence of transverse voltage on source-drain voltage and discussing the results through a diffusion thermopower model.

Contribution

It introduces a method to achieve tunable transverse rectification in a 2DEG using surface gates, with detailed analysis of voltage dependence and underlying mechanisms.

Findings

Transverse voltage is independent of source-drain polarity.

Transverse voltage depends quadratically on source-drain voltage.

Rectification is influenced by density modulation.

Abstract

We demonstrate tunable transverse rectification in a density-modulated two-dimensional electron gas (2DEG). The density modulation is induced by two surface gates, running in parallel along a narrow stripe of 2DEG. A transverse voltage in the direction of the density modulation is observed, i.e. perpendicular to the applied source-drain voltage. The polarity of the transverse voltage is independent of the polarity of the source-drain voltage, demonstrating rectification in the device. We find that the transverse voltage $U_{y}$ depends quadratically on the applied source-drain voltage and non-monotonically on the density modulation. The experimental results are discussed in the framework of a diffusion thermopower model.