Asymmetric power dissipation in electronic transport through a quantum point contact

TL;DR

This paper analyzes how power dissipation in a quantum point contact varies asymmetrically with energy, temperature, and voltage, revealing enhanced asymmetry at conductance steps and higher temperatures.

Contribution

It introduces a detailed evaluation of asymmetric power dissipation in quantum point contacts using the Landauer-Büttiker approach, highlighting conditions that maximize dissipation asymmetry.

Findings

Dissipation asymmetry is most pronounced at conductance steps.

Asymmetry increases with temperature at low temperatures.

Maximum dissipation position is estimated.

Abstract

We investigate the power dissipated by an electronic current flowing through a quantum point contact in a two-dimensional electron gas. Based on the Landauer-B\"uttiker approach to quantum transport, we evaluate the power that is dissipated on the two sides of the constriction as a function of the Fermi energy, temperature, and applied voltage. We demonstrate that an asymmetry appears in the dissipation, which is most pronounced when the quantum point contact is tuned to a conductance step where the transmission strongly depends on energy. At low temperatures, the asymmetry is enhanced when the temperature increases. An estimation for the position of the maximum dissipation is provided.