Planar Hall effect in the quasi-one-dimensional topological superconductor TaSe3

Abstract

A novel planar Hall effect (PHE) is induced by the chiral anomaly or nontrivial Berry curvature, which has been predicted in nonmagnetic Weyl/Dirac semimetals. Recent theories suggest such an effect exists in three-dimensional (3D) topological insulators even in the absence of chiral anomaly. In this paper, we present a detailed analysis of the transport properties in the quasi-1D $\mathrm{Ta}{\mathrm{Se}}_{3}$, a candidate of topological superconductor (TSC) predicted by the theorist. There are some interesting observations on $\mathrm{Ta}{\mathrm{Se}}_{3}$. (1) The electron-hole compensation has been confirmed by the Hall effect measurements around ${T}_{\mathrm{com}}\ensuremath{\sim}30\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, which accounts for the extremely large magnetoresistance in $\mathrm{Ta}{\mathrm{Se}}_{3}$. (2) The remarkable PHE and anisotropic magnetoresistance (AMR) are observed in $\mathrm{Ta}{\mathrm{Se}}_{3}$. Based on the detailed analysis of the PHE and AMR curves, the origin of PHE in $\mathrm{Ta}{\mathrm{Se}}_{3}$ is suggested to originate from the resistivity anisotropy induced by the difference of field-induced anisotropic scattering in surface Dirac fermions of various spins. (3) We observed the successive Fermi surface reconstruction induced by the temperature around ${T}^{*}\ensuremath{\sim}50\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, where the amplitude of intrinsic PHE drops sharply related to the suppression of the topological surface state. Meanwhile, the $d{\ensuremath{\rho}}_{xx}(T)/dT$ curve presents a broad anomaly around ${T}_{\mathrm{peak}}\ensuremath{\sim}70\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, which can be explained as a possible charge-density wave associated with imperfect Fermi surface nesting. PHE provides an effective method to understand the relationship between the electronic transport properties and the topological structure in quasi-1D TSC $\mathrm{Ta}{\mathrm{Se}}_{3}$.