The chiral crystal is characterized by a lack of mirror symmetry and an inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, here we investigate the spin and electronic structure in p-type semiconductor elemental tellurium with a chiral crystal structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the BZ corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehog-like, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.
@article{arxiv.1908.09725,
title = {Radial spin texture in elemental tellurium with chiral crystal structure},
author = {M. Sakano and M. Hirayama and T. Takahashi and S. Akebi and M. Nakayama and K. Kuroda and K. Taguchi and T. Yoshikawa and K. Miyamoto and T. Okuda and K. Ono and H. Kumigashira and T. Ideue and Y. Iwasa and N. Mitsuishi and K. Ishizaka and S. Shin and T. Miyake and S. Murakami and T. Sasagawa and Takeshi Kondo},
journal= {arXiv preprint arXiv:1908.09725},
year = {2020}
}