Quantum Dynamics of Small-Size Triplet Superconductors with Broken Time-Reversal Symmetry

Abstract

Symmetry of the order parameter in some triplet superconductors corresponds to doubly-degenerate chiral states. We predict that in a sufficiently small sample this degeneracy can be lifted via macroscopic quantum tunneling. Moreover, if the initial state is prepared correspondingly, 'instanton'-like quantum behavior is possible in a single-domain sample. In this case coherent oscillations of magnetic momentum should take place, as well as the sign alternations of the boundary currents. In particular, spontaneous Hall-effect recently predicted for ruthenates should posses the oscillating voltage feature.