Torque and temperature dependence of the hysteretic voltage-induced torsional strain in tantalum trisulfide

TL;DR

This study investigates how temperature and applied torque influence the hysteretic voltage-induced torsional strain in tantalum trisulfide, revealing complex dependencies related to charge-density-wave dynamics and residual strain effects.

Contribution

It provides new insights into the voltage, temperature, and torque dependence of VITS in tantalum trisulfide, highlighting the role of residual torsional strain and CDW twists.

Findings

VITS time constant varies with CDW current

Torque affects VITS magnitude and sign

Voltage alters CDW twist pitch

Abstract

We have measured the dependence of the hysteretic voltage-induced torsional strain (VITS) in crystals of orthorhombic tantalum trisulfide on temperature and applied torque. In particular, applying square-wave voltages above the charge-density-wave (CDW) threshold voltage, so as to abruptly switch the strain across its hysteresis loop, we have found that the time constant for the VITS to switch (at different temperatures and voltages) varied as the CDW current. Application of torque to the crystal could also change the VITS time constant, magnitude, and sign, suggesting that the VITS is a consequence of residual torsional strain in the sample which twist the CDW. Application of voltage changes the pitch of these CDW twists, which then act back on the lattice. However, it remains difficult to understand the sluggishness of the response.