Thermodynamic Anomaly Above the Superconducting Critical Temperature in the Quasi One-Dimensional Superconductor Ta$_4$Pd$_3$Te$_{16}$

TL;DR

This study reveals a thermodynamic phase transition in the quasi-one-dimensional superconductor Ta$_4$Pd$_3$Te$_{16}$ at 20 K, affecting transport properties without altering the Fermi surface, indicating a charge order that influences quasiparticle scattering.

Contribution

It uncovers a thermodynamic anomaly above the superconducting transition temperature linked to charge order that does not modify the Fermi surface in Ta$_4$Pd$_3$Te$_{16}$.

Findings

Detection of a phase transition at 20 K affecting conductivity perpendicular to chains.

Fermi surface pockets remain unchanged across the transition.

Charge order influences quasiparticle scattering without breaking translational symmetry.

Abstract

We study the intrinsic transport anisotropy and fermiology of the quasi one-dimensional superconductor Ta$_4$Pd$_3$Te$_{16}$. Below $T^*=20$ K we detect a thermodynamic phase transition that predominantly affects the conductivity perpendicular to the quasi one-dimensional chains, consistent with a thermodynamic transition related to the presence of charge order that precedes superconductivity. Remarkably the Fermi surface pockets detected by de Haas-van Alphen (dHvA) oscillations are unaffected by this transition, suggesting that the ordered state does not break any translational symmetries but rather alters the scattering of the quasiparticles themselves.