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Local Time-Reversal Symmetry Breaking in d_(x2-y2) Superconductors

M. J. Graf·A. V. Balatsky·J. A. Sauls
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Abstract

We show that an isolated impurity in a spin singlet d_{x2-y2} superconductor generates a d_{xy} order parameter with locally broken time-reversal symmetry. The origin of this effect is a coupling between the d_{x2-y2} and the d_{xy} order parameter induced by spin-orbit scattering off the impurity. The signature of locally broken time-reversal symmetry is an induced orbital charge current near the impurity, which generates a localized magnetic field in the vicinity of the impurity. We present a microscopic theory for the impurity induced d_{xy} component, discuss its spatial structure as well as the pattern of induced current and local magnetic field near the localized impurity spin.

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M. J. Graf, A. V. Balatsky, J. A. Sauls. 1999-07-20. Local Time-Reversal Symmetry Breaking in d_(x2-y2) Superconductors. https://doi.org/10.1103/physrevb.61.3255

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