Symmetry-resolved magnetoelastoresistance in multivalley bismuth

TL;DR

This study investigates how magnetic fields and strain influence the electronic valleys in bismuth, revealing that symmetry-resolved magnetoelastoresistance can probe valley-dependent states and their response to external stimuli.

Contribution

It introduces a symmetry-resolved analysis of magnetoelastoresistance in bismuth, highlighting the distinct behaviors of symmetric and antisymmetric components under magnetic fields.

Findings

Symmetric component remains nearly constant with magnetic field.

Antisymmetric component dominates the magnetoelastoresistance response.

Magnetic field modifies valley mobility and induces valley polarization.

Abstract

We report a symmetry-resolved study of longitudinal magnetoelastoresistance (MER) in the multivalley material bismuth, with the current, uniaxial stress, and magnetic field all applied along the binary axis. The magnitude of MER exhibits a steep increase at low magnetic fields, reaches a peak, and then gradually decreases at higher fields. By decomposing the strain response into symmetric and antisymmetric symmetry channels, we reveal contrasting magnetic field dependencies. Despite the overall non-monotonic field dependence of the MER, the symmetric component remains nearly constant under magnetic fields, suggesting that the valleys in bismuth preserve a rigid-band nature against strain even in the presence of a magnetic field. In contrast, the antisymmetric component, associated with mobility anisotropy, dominates the MER response in a magnetic field. At low magnetic fields, the applied field effectively modifies the apparent mobility of each valley, leading to an enhancement in the magnitude of the antisymmetric MER. At higher fields, field-induced valley polarization further modifies this mobility anisotropy by altering the contributions from each valley's mobility, accounting for the moderate suppression of the MER. These findings demonstrate that symmetry-resolved MER serves as a powerful probe of valley-dependent electronic states and provides a fundamental platform for understanding the interplay between magnetic field, strain, and charge transport.