The Chiral Induced Spin Selectivity Effect -- What It Is, What It Is Not, And Why It Matters

Abstract

The chiral induced spin selectivity effect is an excited states phenomenon, which can be probed using photospectroscopy as well as transport measurements. On the one hand such measurements represent averaged quantities, on the other hand nearly all theoretical descriptions, with only a few exceptions, have been concerned with energy dependent properties of the pertinent structures. While those properties may or may not be relevant for the chiral induced spin selectivity effect, many of those properties have been attributed as being the, or part of the, origins of the effect. Here, it is demonstrated that, for instance, the spin-resolved transmission provides little, if any, information about the chiral induced spin selectivity effect. Moreover, although effective single-electron theory can be used in this context, reasons are given for why such descriptions are not viable.

A group-theoretic approach to the origin of chirality-induced spin selectivity in non-magnetic molecular junctions

“…The CISS effect in this context is usually identified with a finite magneto-conductance measured in transport experiments in the non-linear response regime 37,38,47 . The microscopic origin of the CISS effect is being actively debated and may be attributed to a combination of factors such as the chirality of the molecule, the strength of SOC in the system, electron correlations, dephasing effects, and a finite bias voltage 43,[47][48][49][50][51][52][53] . At least one of these factors, the strength of SOC in the normal metal…”