Analysis of impurity-induced circular currents for the chiral superconductor Sr_{2}RuO_{4}

Abstract

The microscopic mechanism of circular currents induced in the vicinity of a non-magnetic impurity is analyzed for the (time-reversal symmetry breaking) chiral superconducting state $\mathbf{d}(\mathbf{k})=\hat{\mathbf{z}}(k_x\pm i{k}_y)$ which is very likely realized in Sr_2RuO_4. From the analytic, not self-consistent solution of the Bogolyubov-de Gennes equations we find two types of quasiparticle states, a bound state and the continuum state. Through impurity scattering the condensate transfers angular momentum to the quasiparticle states which generate a circular current. At low temperature the continuum part of the quasiparticle spectrum gives the main contribution. The non-selfconsistent solution yields a state of finite angular momentum. The comparison with the corresponding Ginzburg-Landau theory reveals the existence of a compensating counterflow created by the superconducting condensate. The currents and magnetic fields appearing around the impurity have possibly been observed by muon spin relaxation measurements.

16 page Latex, 3PS file, accepted by J.Phys.Soc.Jpn

Cited by in corpus (13)

• Two-dimensional p-wave superconducting states with magnetic moments on a conventional s-wave superconductor
• Single Impurity Effects in Multiband Superconductors with Different Sign Order Parameters
• Spontaneous surface flux pattern in chiral p-wave superconductors - revisited
• Numerical Renormalization Group Study of Kondo Effect in Unconventional Superconductors
• Orbital effect of Cooper pairs on Kondo effect in unconventional superconductors
• Impact of random impurities on the anomalous Hall effect in chiral superconductors
• Anomalous Hall effect in single-band chiral superconductors from impurity superlattices
• The energy-level statistics in the core of a vortex in a p-wave superconductor
• Impurity Bound States and Symmetry of the Superconducting Order Parameter in Sr_2RuO_4
• Current patterns and magnetic impurities in time-reversal breaking superconductor
• Impurity Site NMR Relaxation in Unconventional Superconductors
• Enhanced Coherence of Antinodal Quasiparticles in a Dirty d-wave Superconductor
• Effect of spin-orbit impurity scattering in the superconducting state of t-J model