Quasiparticle Delocalization Induced by Novel Quantum Interference in Disordered d-Wave Superconductors

TL;DR

This paper investigates how a novel quantum interference process in disordered d-wave superconductors leads to quasiparticle delocalization, revealing extended states and the conditions under which this effect is suppressed.

Contribution

It introduces a new quantum interference mechanism causing weak-antilocalization in quasiparticle transport, highlighting the role of particle-hole symmetry and impurity scattering limits.

Findings

Weak-antilocalization correction indicates extended quasiparticle states

Correction is suppressed near unitarity and nesting due to particle-hole symmetry

Delocalization depends on impurity scattering strength and symmetry conditions

Abstract

The diagrammatic approach is applied to study quasiparticle transport properties in two-dimensional d-wave superconductors with dilute nonmagnetic impurities both in Born and in unitary limits. It is found that a novel quantum interference process gives rise to a weak-antilocalization correction to the spin conductivity, indicating the existence of extended low-energy quasiparticle states. With comimg close to unitarity and the nesting, this correction is suppressed and eventually vanishes due to the global particle-hole symmetry.