Nonlinear electrical transport phenomena as fingerprints of a topological phase transition in ZrTe5

Abstract

Topological phase transitions, influenced by magnetic fields, dopants, pressure, and temperature, create Berry curvature in band structures, challenging to detect due to resolution and scattering issues in spectroscopy and transport. Here, we propose nonlinear electrical transport phenomena as fingerprints of a topological phase transition in ZrTe5 under magnetic fields. Both a nonlinear longitudinal conductivity ΔσL in a magnetic-field-aligned electric field and a third-order nonlinear Hall (transverse) conductivity Δσxy in a magnetic-field-perpendicular electric field arise below a characteristic temperature T*. The sensitivity of nonlinear transport to the band topology allows the detection of a subtle change in the band topology hidden in linear transport coefficients. Extending the previous scaling theory between linear transport coefficients (σxx and σxy), we also propose scaling relations for both linear (σxx and σxy) and nonlinear (ΔσL and Δσxy) transport coefficients. These scaling relations will help understand the interplay between the mechanisms of nonlinear transport coefficients and the influence of Berry curvature.