Electronic structure and spontaneous internal field around non-magnetic impurities in spin-triplet chiral p-wave superconductors

TL;DR

This study investigates the electronic structure and internal magnetic fields around impurities in spin-triplet chiral p-wave superconductors, proposing a method to distinguish pairing states via local magnetic field measurements.

Contribution

It provides a detailed analysis of impurity effects in different chiral p-wave states using Bogoliubov-de Gennes theory, highlighting how to differentiate pairing symmetries.

Findings

Distinct local density of states for different pairing states

Spontaneous currents around impurities vary with pairing symmetry

Magnetic field patterns can identify the pairing state

Abstract

The electronic structure around an impurity in spin triplet p-wave superconductors is studied by the Bogoliubov-de Gennes theory on a tight-binding model, where we have chosen $\sin{p_x}{+}{\rm i}\sin{p_y}$-wave or $\sin{(p_x+p_y)}{+}{\rm i}\sin{({-}p_x{+}p_y)}$-wave states which are considered to be candidates for the pairing state in Sr$_{2}$RuO$_{4}$. We calculate the spontaneous current and the local density of states around the impurity and discuss the difference between the two types of pairing. We propose that it is possible to discriminate the two pairing states by studying the spatial dependence of the magnetic field around a pair of impurities.