Cooper Pairs with Broken Parity and Time-Reversal Symmetries in D-wave Superconductors

TL;DR

This paper explores how paramagnetic effects induce a triplet component in the order parameter of d-wave superconductors, breaking parity and time-reversal symmetries, especially in vortex phases of modern superconductors.

Contribution

It introduces the concept of a triplet component arising from paramagnetic effects in vortex phases of d-wave superconductors, highlighting broken symmetries and a generic phase diagram.

Findings

Triplet component of order parameter appears without impurities.

Broken parity and time-reversal symmetries in vortex phases.

Order parameter component can be of order unity in certain superconductors.

Abstract

Paramagnetic effects are shown to result in the appearance of a triplet component of order parameter in a vortex phase of a d-wave superconductor in the absence of impurities. This component, which breaks both parity and time-reversal symmetries of Cooper pairs, is expected to be of the order of unity in a number of modern superconductors such as organic, high-Tc, and some others. A generic phase diagram of such type-IV superconductors, which are singlet ones at H=0 and characterized by singlet-triplet mixed Copper pairs with broken time-reversal symmetry in a vortex phase, is discussed.