2020/02/29 by Atsuo Shitade, Emi Minamitani · 1 citation
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1088/1367-2630/abc920
published as New J. Phys. 22 113023 (2020) · 7 pages, 2 figures
arxiv created 2020/11/23 · arxiv updated 2020/11/24
We report a new type of spin-orbit coupling (SOC) called geometric SOC. Starting from the relativistic theory in curved space, we derive an effective nonrelativistic Hamiltonian in a generic curve embedded into flat three dimensions. The geometric SOC is O(m-1), in which m is the electron mass, and hence much larger than the conventional SOC of O(m-2). The energy scale is estimated to be a hundred meV for a nanoscale helix. We calculate the current-induced spin polarization in a coupled-helix model as a representative of the chirality-induced spin selectivity. We find that it depends on the chirality of the helix and is of the order of 0.01 ℏ per \rm nm when a charge current of 1~\rm μA is applied.