An excitonic magnet hosts a condensate of spin-triplet excitons composed of conduction-band electrons and valence-band holes, and may be described by the two-orbital Hubbard model. When the Hamiltonian has the nearest-neighbor interorbital hopping integrals with d-wave symmetry and the number of electrons is slightly away from half filling, the k-space spin texture appears in the excitonic phase with a broken time-reversal symmetry. We then show that, applying electric field to this doped excitonic magnet along a particular direction, a pure spin current emerges along its orthogonal direction. We discuss possible experimental realization of this type of the pure spin current in actual materials.
@article{arxiv.2002.02131,
title = {Emergence of pure spin current in doped excitonic magnets},
author = {Shunsuke Yamamoto and Koudai Sugimoto and Yukinori Ohta},
journal= {arXiv preprint arXiv:2002.02131},
year = {2020}
}