Chirality-Induced Orbital Selectivity through Linear-Orbital Coupling

Abstract

We present a three-dimensional continuum model of electron transmission through a chiral electrostatic potential and show that it gives rise to chirality-induced orbital selectivity. In this model, electron transmittance depends strongly on the incident orbital angular momentum (OAM) associated with its transverse motion, and the selectivity reverses when the potential's handedness is inverted. The effect originates from a coupling between axial linear momentum and OAM mediated by the helical spatial dependence of the potential. For DNA-scale geometric parameters, this linear-orbital coupling produces sizable orbital selectivity, which remains robust to static and dynamic disorder, and increases with the length of chiral regions. Although bare spin-orbit coupling in the chiral potential considered here is too weak to generate considerable spin dynamics, spin-OAM correlations in the electrodes allow the same orbital selective mechanism to induce appreciable spin selectivity. These results identify orbital dynamics as an important contributor to electron transport in chiral systems.