Nuclear Spin Relaxation Rate of Disordered $p_x+ip_y$-wave Superconductors

TL;DR

This study investigates how disorder affects the spin-lattice relaxation rate in $p_x+ip_y$-wave superconductors, revealing disorder-induced changes in temperature dependence consistent with experimental observations.

Contribution

It provides a numerical analysis of impurity effects on $p_x+ip_y$-wave superconductors using the Bogoliubov-de Gennes framework, highlighting novel power law behaviors.

Findings

Coherence peak in $1/T_1$ observed in clean limit.

Strong scattering induces two distinct power law regimes.

Results align with nuclear quadrupolar resonance experiments.

Abstract

Based on an effective Hamiltonian with the binary alloy disorder model defined in the triangular lattice, the impurity scattering effects on the density of states and especially on the spin-lattice relaxation rate $1/T_1$ of $p_x+ip_y$-wave superconductors are studied by solving numerically the Bogoliubov-de Gennes equations. In the clean limit, the coherence peak of $1/T_1$ is observed as expected. More intriguingly, for strong scattering potential, the temperature dependence of $1/T_1$ exhibits the two different power law behaviors near $T_{\text{c}}$ and at low temperatures, respectively, which is in good agreement with the nuclear quadrupolar resonance measurement.