Nonhelical spin texture in the normal states of the centrosymmetric superconductor β−PdBi2

Abstract

A nonhelical spin texture was observed in the centrosymmetric superconductor beta-PdBi2 using an imaging-type spin- and angle-resolved spectroscopy. The observed surface and bulk states near the Fermi energy are found to be spin polarized with nonhelical textures. First-principles calculations and effective models show that the inter-and intralayer hoppings account for the complex spin texture and thus play a significant role in the spatial distribution of the layer-locked spin states. Our work not only provides insights into the local spin states in inversion-symmetric systems but also paves the way to the identification of the nature of superconducting pairing in the presence of a complex spin texture in beta-PdBi2 and the related centrosymmetric superconductors.