Magnetic impurity induced id_{xy} component and spontaneous time reversal and parity breaking in a d_{x^2-y^2}-wave superconductor

Abstract

It is shown that the patches of complex d_{xy} component are generated around magnetic impurity in the presence of the coupling between orbital moment of the condensate and impurity spin S. Locally induced d_{xy} gap leads to the fully gapped quasiparticle spectrum near impurity. The phase of the induced i d_{xy} component is determined by impurity spin and averages to zero at high temperatures. It is suggested that at low temperature the well defined patches of d_{xy} are formed and they can undergo a phase transition into phase locked state via Josephson effect. Violation of time-reversal symmetry and parity occurs spontaneously via the second order transition. In the ordered phase both impurity magnetization and d_{xy} component of the order parameter develop and are proportional to each other.