Quenched and Negative Hall Effect in Periodic Media: Application to Antidot Superlattices

TL;DR

This paper reveals that electrons can move opposite to the expected E x B drift in 2D periodic potentials, causing negative Hall resistivity, explained through chaotic trajectories and observed in antidot superlattices.

Contribution

It demonstrates the phenomenon of negative Hall effect in periodic media and explains its origin via chaotic channeling trajectories, with experimental validation.

Findings

Electrons move opposite to E x B drift in periodic potentials.

Negative Hall resistivity observed at small magnetic fields.

Chaotic trajectories cause the reversed electron motion.

Abstract

We find the counterintuitive result that electrons move in OPPOSITE direction to the free electron E x B - drift when subject to a two-dimensional periodic potential. We show that this phenomenon arises from chaotic channeling trajectories and by a subtle mechanism leads to a NEGATIVE value of the Hall resistivity for small magnetic fields. The effect is present also in experimentally recorded Hall curves in antidot arrays on semiconductor heterojunctions but so far has remained unexplained.