Circuit-Model Analysis for Spintronic Devices with Chiral Molecules as Spin Injectors

Recent research discovered that charge transfer processes in chiral molecules can be spin selective and named the effect Chiral-Induced Spin Selectivity (CISS). Follow-up work studied hybrid spintronic devices with conventional electronic materials and chiral (bio)molecules. However, a theoretical foundation for the CISS effect is still in development and the spintronic signals were not evaluated quantitatively. We present a circuit-model approach that can provide this quantitative evaluation. Our analysis assumes the scheme of a recent experiment that used photosystem~I as spin injectors. We find that the CISS effect can indeed give signals that are strong enough for detection, but also that the observed signals are two orders of magnitude higher than what the CISS effect can provide, indicating that in practice other phenomena can dominate the signals. Our approach provides a generic framework for analyzing this type of experiments and advancing the understanding of the CISS effect.