2025/12/01 by Kato, Takemitsu, Utsumi, Yasuhiro, Entin-Wohlman, Ora +1
#FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2512.01504
We derive the interatomic spin-orbit interaction (SOI) from a helical atomic chain composed of p-orbitals with intra-atomic SOI, which exhibits a helical state--a potential origin of the chiral-induced spin selectivity (CISS) effect. In this model, a strong crystal field in the tangential direction of the helix leads to the formation of energetically separated σ- and π-bands. In the second-order process, a spin in the σ-orbital virtually hops to the π-orbital, flips its direction due to intra-atomic SOI, and then hops back to the σ-orbital in the neighboring atom due to the misalignment of p-orbitals along the helix. This process induces an interatomic SOI in the σ-band, which takes the form of a Rashba-type SOI generated by an electric field normal to the helical axis. The magnitude of the SOI is proportional to the curvature, the hopping energy, the intra-atomic SOI energy, and inversely proportional to the crystal field strength. The second-order process also induces long-range second-nearest-neighbor hoppings. We analytically derive the spin-split band structure in the zero-torsion limit.