Non-monotonic magnetoresistance of two-dimensional electron systems in the ballistic regime

TL;DR

This paper reports a universal, non-monotonic magnetoresistance behavior in two-dimensional electron systems in the ballistic regime, showing a maximum at certain magnetic fields that varies with temperature, and compares experimental data with theoretical models.

Contribution

It presents the first experimental observation of non-monotonic magnetoresistance in 2D electron systems in the ballistic regime and compares findings with existing theoretical predictions.

Findings

Magnetoresistance exhibits a maximum at fields B>1/μ.

Maximum magnetoresistance increases with temperature.

Effect observed across various Si- and GaAs-based systems.

Abstract

We report experimental observations of a novel magnetoresistance (MR) behavior of two-dimensional electron systems in perpendicular magnetic field in the ballistic regime, for k_BT\tau/\hbar>1. The MR grows with field and exhibits a maximum at fields B>1/\mu, where \mu is the electron mobility. As temperature increases the magnitude of the maximum grows and its position moves to higher fields. This effect is universal: it is observed in various Si- and GaAs- based two-dimensional electron systems. We compared our data with recent theory based on the Kohn anomaly modification in magnetic field, and found qualitative similarities and discrepancies.