Non-Ohmic negative longitudinal magnetoresistance in two-dimensional electron gas

TL;DR

This study reveals that negative longitudinal magnetoresistance in a two-dimensional electron gas is influenced by measurement current, with quantum interference and disorder effects playing key roles, offering new insights into electrotransport phenomena beyond Weyl semimetals.

Contribution

It demonstrates non-Ohmic NLMR in a non-Weyl 2D electron gas and highlights the impact of measurement current on magnetoresistance behavior.

Findings

NLMR persists up to 130 K

NLMR magnitude depends on current below 60 K

Quantum interference and disorder scattering explain the tunable NLMR

Abstract

Negative longitudinal magnetoresistance (NLMR) has been reported in a variety of materials and has attracted extensive attention as an electrotransport hallmark of topological Weyl semimetals. However, its origin is still under debate. Here, we demonstrate that the NLMR in a two dimensional electron gas can be influenced by the measurement current. While the NLMR persists up to 130 K, its magnitude and magnetic field response become dependent on the applied current below 60 K. The tunable NLMR at low and high currents can be best attributed to quantum interference and disorder scattering effects, respectively. This work uncovers non-Ohmic NLMR in a non-Weyl material and highlights potential effects of the measurement current in elucidating electrotransport phenomena. We also demonstrate that NLMRs can be a valuable phenomenon in revealing the origins of other properties, such as negative MRs in perpendicular magnetic fields.