Out-of-plane resonant localized-spin polarization in graphene nanoribbons with nonmagnetic adsorbates
Phys. Rev. B 112, 235407 – Published 3 December, 2025
DOI: https://doi.org/10.1103/yp9m-dxqz
Abstract
Spin transport in time-reversal symmetric multichannel wire systems with only one propagating channel is known to be spin independent, with no spin polarization in the transmitted flux for unpolarized incident flux. In this work we show that out-of-plane resonant localized-spin polarization (RLSP) does occur, while the transport remains spin independent, in graphene nanoribbons with nonmagnetic adsorbate-induced spin-orbit interaction (SOI). This RLSP result is shown associated with evanescent subbands. Equally crucial, the most significant contribution is from the intrasubband interference, between the spin-dependent and the spin-independent parts of an evanescent subband in the scattering state. The resonance is enabled by (1) on-site potentials acted by the SOI adsorbates upon its surrounding carbon sites, and (2) large band-edge density-of-states effects from an evanescent subband. This resonance, with energies close to the evanescent-subband band edge, largely enhances the RLSP results. The sign of the spin polarization is determined by that of the SOI coupling parameter and the transport direction.
