Local current distribution at large quantum dots (QDs): a self-consistent screening model

TL;DR

This paper presents a self-consistent screening model to analyze local current distribution in large quantum dots, revealing that non-dissipative current is confined to incompressible strips and is highly sensitive to magnetic fields.

Contribution

The study introduces a combined self-consistent Thomas-Fermi screening and local Ohm's law approach to model current distribution in large quantum dots, advancing understanding of edge channel formation.

Findings

Non-dissipative current confined to incompressible strips

Current distribution highly sensitive to magnetic field

Supports phenomenological models of edge channel transport

Abstract

We report the implementation of the self-consistent Thomas-Fermi screening theory, together with the local Ohm's law to a quantum dot system in order to obtain local current distribution within the dot and at the leads. We consider a large dot (size $>700$ nm) defined by split gates, and coupled to the leads. Numerical calculations show that the non-dissipative current is confined to the incompressible strips. Due to the non-linear screening properties of the 2DES at low temperatures, this distribution is highly sensitive to external magnetic field. Our findings support the phenomenological models provided by the experimental studies so far, where the formation of the (direct) edge channels dominate the transport.