Chirality-Induced Spin Selectivity: A Minimal Model

Chirality-induced spin selectivity (CISS) is an intriguing yet poorly understood phenomenon observed when electrons travel through a chiral medium or molecule. We propose a current-constrained approach to drive a current through a linear Hubbard chain of twisted p orbitals, thus simulating the electron motion through a chiral molecular system. In this original approach, CISS can be addressed in systems with correlated electrons coupled to nonadiabatic molecular vibrations. Sizable CISS responses are obtained in some parameter space, with a clear amplification of CISS in non-half-filled systems. Peierls vibrations play a special role: CISS cannot be observed in a Hubbard chain in the lack of next nearest neighbor interactions, but an out-of-equilibrium stretching mode can lead to finite polarization even in these systems.