Anisotropic magnetoresistance of charge-density wave in $o$-TaS$_3$

TL;DR

This study investigates the anisotropic magnetoresistance of charge-density waves in $o$-TaS$_3$, revealing a two-fold symmetry and anisotropy linked to interchain coupling, with implications for understanding quantum interference in CDWs.

Contribution

It provides the first detailed analysis of the anisotropic magnetoresistance in $o$-TaS$_3$ charge-density waves, highlighting the role of interchain coupling and quantum interference effects.

Findings

Negative magnetoresistance observed in nonlinear regime.

Magnetoresistance exhibits two-fold angular symmetry.

Maxima occur when magnetic field aligns with the $a$-axis.

Abstract

We report the magnetoresistance of a charge-density wave (CDW) in $o$-TaS$_3$ whiskers at 4.2 K under a magnetic field up to 5.2 T. An anisotropic negative magnetoresistance is found in the nonlinear regime of current-voltage characteristics. The angle dependence of the magnetoresistance, studied by rotating the magnetic field upon the $c$-axis, exhibited a two-fold symmetry. The magnetoresistance amplitude exhibits maxima when the field is parallel to the $a$-axis, whereas it vanishes to the $b$-axis. The observed anisotropy may come from difference in interchain coupling of adjacent CDWs along the $a$- and $b$-axes. Comparison of the anisotropy to the scanning tunneling microscope image of CDWs allows us to provide a simple picture to explain the magnetoresistance in terms of delocalization of quantum interference of CDWs extending over the $b$-$c$ plane.