Impurity Quantum Phase Transition in a Current-Carrying d-Wave Superconductor

TL;DR

This paper investigates how a supercurrent affects an Anderson impurity in a d-wave superconductor, revealing that the impurity state is fully screened at non-zero currents and exhibits a Kosterlitz-Thouless type quantum phase transition.

Contribution

It introduces a numerical analysis of impurity behavior under supercurrent in d-wave superconductors, highlighting a quantum phase transition consistent with Kosterlitz-Thouless theory.

Findings

Impurity state is fully screened at non-zero supercurrent.

Quantum criticality aligns with Kosterlitz-Thouless transition.

Supercurrent influences impurity screening in d-wave superconductors.

Abstract

We study an Anderson impurity embedded in a d-wave superconductor carrying a supercurrent. The low-energy impurity behavior is investigated by using the numerical renormalization group method developed for arbitrary electronic bath spectra. The results explicitly show that the local impurity state is completely screened upon the non-zero current intensity. The impurity quantum criticality is in accordance with the well-known Kosterlitz-Thouless transition.