Magnetoelectric effects and spin switching phenomena at the interface of chiral domains in spin-triplet superconductors

Abstract

Spin-triplet superconductors with time-reversal symmetry breaking can naturally lead to chiral domain walls in their interior. We study the magnetic properties emerging at the interface of chiral domains with opposite winding by focusing on the effects of a superconducting phase drop across the wall and an applied electric gating. The local inversion symmetry breaking at the domain wall drives mixed singlet-triplet pairing configurations that allow a phase- and electric-controllable magnetization with resulting parallel or antiparallel orientations on the two sides of the domain wall. The magnetic switching is also generally accompanied by both spin and charge currents flowing along the edges, whose amplitudes depend on the achieved parallel or antiparallel magnetic phase. The specific magnetoelectric properties of chiral domains with zero or nonvanishing net magnetization near the wall may have several implications. They can be employed to detect the presence of unconventional pairing as well as to design information storage units based on spin-polarized states attached to topological defects.