Optical spin transport theory of spin-1/2 topological Fermi superfluids
Abstract
We theoretically investigate optical (frequency-dependent) bulk spin transport properties in a spin-1/2 topological Fermi superfluid. We specifically consider a one-dimensional system with an interspin {\it p}-wave interaction, which can be realized in ultracold atom experiments. Developing the BCS-Leggett theory to describe the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) evolution and the topological phase transition in this system, we show how the spin transport reflects these many-body aspects. We find that the optical spin conductivity, which is a small AC response of a spin current, shows the spin gapped spectrum in the wide parameter region and the gap closes at topological phase transition point. Moreover, the validity of the low-energy effective model of the Majorana zero mode is discussed along the BCS-BEC evolution in connection with the scale invariance at {\it p}-wave unitarity.
Keywords
Cite
@article{arxiv.2109.14505,
title = {Optical spin transport theory of spin-1/2 topological Fermi superfluids},
author = {Hiroyuki Tajima and Yuta Sekino and Shun Uchino},
journal= {arXiv preprint arXiv:2109.14505},
year = {2024}
}
Comments
10 pages, 5 figures, accepted version for publication in Phys. Rev. B