Chirality-induced spin selectivity

Chirality-induced spin selectivity (CISS) refers to multiple phenomena where handedness of a chiral chemical compound influences the spin of transmitted or emitted electrons.

Experiments were able to demonstrate the effect in the form of polarization of electrons scattered from chiral molecules, spin-dependent transmission probabilities through layers of chiral molecules, spin-selectivity of electron-transport in a chiral medium and enantio-selectivity in chemical reactions induced by spin-polarized electrons.

Theoretical models were able to qualitatively explain the effect using spin-orbit coupling (SOC). But quantitatively the predicted effect was always orders of magnitude smaller than what was measured in experiments. The mechanism underlying CISS is not completely understood.