# Spin-Orbital Hallmarks of Unconventional Superconductors Without Inversion Symmetry

## TL;DR

This paper investigates how spin-orbital polarization patterns in momentum space serve as distinctive indicators of unconventional superconductivity in non-inversion symmetric systems, revealing topological transitions and the interplay of spin-triplet and orbital effects.

## Contribution

It provides a general framework for understanding spin-orbital textures in non-centrosymmetric superconductors and uncovers a topological transition related to spin-winding around nodal points.

## Key findings

- Spin-texture variation is influenced by spin-triplet d-vector and inversion asymmetry g-vector.
- Identification of a topological transition in spin-winding around nodal points.
- Orbital polarization patterns can reveal the nature of the superconducting state.

## Abstract

The spin-orbital polarization of superconducting excitations in momentum space is shown to provide distinctive marks of unconventional pairing in the presence of inversion symmetry breaking.Taking the prototypical example of an electronic system with atomic spin-orbit and orbital-Rashba couplings, we provide a general description of the spin-orbital textures and their most striking changeover moving from the normal to the superconducting state. We find that the variation of the spin-texture is strongly imprinted by the combination of the misalignment of spin-triplet d-vector with the inversion asymmetry g-vector coupling and the occurrence of superconducting nodal excitations. Remarkably, the multi-orbital character of the superconducting state allows to unveil a unique type of topological transition for the spin-winding around the nodal points. This finding indicates the fundamental topological relation between chiral and spin-winding in nodal superconductors. By analogy between spin- and orbital-triplet pairing we point out how orbital polarization patterns can be also employed to assess the character of the superconducting state.