Edge channel mixing induced by potential steps in an integer quantum Hall system

TL;DR

This paper studies how potential steps in an integer quantum Hall system cause mixing of edge channels, showing that multiple steps or specific potential heights can lead to significant mixing, with implications for quantum transport control.

Contribution

It demonstrates that series of potential steps can induce substantial edge channel mixing, and explores effects of smoothened steps on charge density, advancing understanding of quantum Hall edge dynamics.

Findings

Single step induces few percent mixing

Series of steps can yield up to 50% mixing

Strong mixing occurs at specific potential heights

Abstract

We investigate the coherent mixing of co-propagating edge channels in a quantum Hall bar produced by step potentials. In the case of two edge channels it is found that, although a single step induces only a few percent mixing, a series of steps could yield 50% mixing. In addition, a strong mixing is found when the potential height of a single step allows a different number of edge channels on the two sides of the step. Charge density probability has been also calculated even for the case where the step is smoothened.