Thermal Transport Properties of Bechgaard Salts (TMTSF)2PF6 and (TMTSF)2ClO4: Implication of Spin-Charge Separation

TL;DR

This study investigates the thermal transport properties of Bechgaard salts, revealing significant magnon-drag effects and evidence of spin-charge separation in their metallic states, with implications for understanding low-dimensional quantum materials.

Contribution

First measurements of thermal transport in (TMTSF)2ClO4 and (TMTSF)2PF6 showing magnon-drag effects and spin-charge separation evidence in these quasi-one-dimensional salts.

Findings

Magnon-drag effects contribute to thermopower above 80 K.

Spin-charge separation is indicated in the metallic state.

Thermal conductivity remains linear and unaffected by disorder below 25 K.

Abstract

We report thermal transport measurements performed on the quasi-one-dimensional Bechgaard salts (TMTSF)2ClO4 and (TMTSF)2PF6 along the a-direction. For both salts, magnon-drag effects are found to contribute considerably to thermopower above 80 K. These results imply spin-charge separation in the metallic state for both salts. Moreover, a linear temperature-dependent thermal conductivity is found to be unaffected by anion disorder below an anion ordering transition temperature TAO~25 K in (TMTSF)2ClO4.