Topological spin texture and d-vector rotation in spin-triplet superconductors: A case of UTe2

TL;DR

This paper theoretically predicts a topologically rich spin texture with half-quantized vortices in spin-triplet superconductor UTe2, explaining recent experimental observations of d-vector rotation and suggesting experimental signatures for pairing symmetry.

Contribution

It introduces a novel topological spin texture with half-quantized vortices in UTe2, linking it to experimental phenomena and potential detection methods.

Findings

Discovery of a stable topological spin texture with half-quantized vortices.

Explanation of d-vector rotation phenomena in UTe2.

Predictions for experimental signatures like Majorana modes and NMR responses.

Abstract

A novel spin texture formed by Cooper pair spins is found theoretically with a phase string attached by half-quantized vortices at both ends in a unit cell and characterized by its topologically rich vortex structure in a spin-triplet pairing. It is stable at an intermediate field region sandwiched by two conventional singular vortex phases below and above it. The d-vector direction of this spin texture is tilted from the principal crystal axes, whose spin susceptibility is neither the normal Pauli one \c{hi}N nor zero, describing microscopically the process of the d-vector rotation phenomena observed recently in UTe2. We compare the spin texture and singular vortex state in relation to the quasi-particle structure with Majorana zero modes for STM, the nuclear spin resonance spectral line width for NMR and {\mu}SR, and the vortex form factors for SANS to facilitate the identification of the pairing symmetry in UTe2.