Heat Conduction in the Heavy Fermion Superconductor $UPd_2Al_3$

TL;DR

This study measures thermal conductivity in UPd2Al3, revealing residual quasiparticle states at low temperatures, supporting theories of unconventional superconductivity with gap nodes.

Contribution

First measurements of thermal conductivity in UPd2Al3 in both normal and superconducting states at low temperatures.

Findings

Superconducting state shows about 10% residual linear term in thermal conductivity.

Results support impurity scattering theories for unconventional superconductors.

Comparison with other U-based superconductors highlights similarities and differences.

Abstract

We present preliminary measurements of the thermal conductivity of the heavy fermion superconductor UPd$_2$Al$_3$ for the normal and superconducting states at low temperatures. As T$\to$0, the superconducting state is characterized by a finite linear term, about 10% of the normal state value, which suggests a residual density of low energy quasiparticle states. This agrees qualitatively with resonant impurity scattering theories applied to exotic superconductors with nodes in the gap structure. Comparisons are made with theory and with other U-based superconductors, such as URu$_2$Si$_2$ and UPt$_3$.