Topological Phase Transition and Chiral-Anomaly Driven Negative Magneto-Resistance in Bulk Black Phosphorus

TL;DR

This study investigates how black phosphorus undergoes a topological phase transition under pressure, revealing negative magnetoresistance driven by chiral anomaly effects associated with a Lifshitz transition.

Contribution

It demonstrates the pressure-induced topological Lifshitz transition in black phosphorus and links negative magnetoresistance to chiral anomaly effects in this material.

Findings

Black phosphorus transitions from a band semiconductor to a Dirac semimetal under pressure.

Negative magnetoresistance appears only in the B//I configuration during the transition.

Chiral anomaly contributes to the observed negative magnetoresistance.

Abstract

We report the anisotropic magneto-transport measurement on a non-compound band semiconductor black phosphorus (BP) with magnetic field B up to 16 Tesla applied in both perpendicular and parallel to electric current I under hydrostatic pressures. The BP undergoes a topological Lifshitz transition from band semiconductor to a zero-gap Dirac semimetal state, characterized by a weak localization-weak antilocaliation transition at low magnetic fields and the emergence of a nontrivial Berry Phase of detected by SdH magneto-oscillations in magnetoresistance curves. In the transition region, we observe a pressure-dependent negative MR only in the B//I configuration. This negative longitudinal MR is attributed to the Adler-Bell-Jackiw anomaly (topological E$\cdot$B term) in the presence of weak antilocalization corrections.