Mesoscopic Diffusion Thermopower in Two-Dimensional Electron Gases

TL;DR

This paper investigates how energy diffusion in mesoscopic two-dimensional electron gases creates thermopower, emphasizing the role of device geometry and potential profiles, and proposes methods to measure the energy diffusion length.

Contribution

It introduces a diffusion thermopower model for mesoscopic 2D electron gases and suggests experimental schemes to determine the energy diffusion length and its dependence on gate voltage.

Findings

Thermopower depends on device size and potential profile.

Proposed measurement schemes for energy diffusion length.

Model explains mesoscopic thermopower behavior.

Abstract

The diffusion of energy that is locally deposited into two-dimensional electron gases by Joule heating generates transverse voltages across devices with broken symmetry. For mesoscopic structures characterized by device dimensions comparable to the energy diffusion length, the resulting thermopower strongly depends on details of the potential profile defined by electric gates. We discuss these mesoscopic features within a diffusion thermopower model and propose schemes to measure the energy diffusion length and its dependence on gate voltage.