Robust Nodal Behavior in the Thermal Conductivity of Superconducting UTe_{2}

Robust Nodal Behavior in the Thermal Conductivity of Superconducting UTe_{2}

Blog Article

The superconducting state SCOOP of the heavy-fermion metal UTe_{2} has attracted considerable interest because of evidence of spin-triplet Cooper pairing and nontrivial topology.Progress on these questions requires identifying the presence or absence of nodes in the superconducting gap function and their dimension.In this article, we report a comprehensive study of the influence of disorder on the thermal transport in the superconducting state of UTe_{2}.

Through detailed measurements of the magnetic-field dependence of the thermal conductivity in the zero-temperature limit, we obtain clear evidence of the presence of point nodes in the superconducting gap for all samples with transition temperatures ranging from 1.6 to 2.1 K obtained by different synthesis methods, including a refined self-flux method.

This robustness implies the presence of symmetry-imposed nodes throughout the range studied, further confirmed via disorder-dependent calculations of the thermal transport in a model with a single pair of nodes.In addition to capturing the temperature dependence of the thermal conductivity up to T_{c}, this model provides some information about the locations of the nodes, suggesting a B_{1u} or B_{2u} symmetry for the superconducting order parameter.Additionally, comparing the new, ultrahigh conductivity samples to older samples reveals a crossover between a low-field and Headband a high-field regime at a single value of the magnetic field in all samples.

In the high-field regime, the thermal conductivity at different disorder levels differs from each other by a simple offset, suggesting that some simple principle determines the physics of the mixed state, a fact which may illuminate trends observed in other clean nodal superconductors.