Role of chiral-induced spin selectivity in the radical pair mechanism of avian magnetoreception

In this paper, we investigate the effect of chiral-induced spin selectivity (CISS) on the radical pair mechanism of avian magnetoreception. We examine the impact of spin selectivity on the avian compass sensitivity. In this analysis, we also consider the dipolar and exchange interactions and observe their interplay with CISS. We find that CISS results in a multifold increase in avian compass sensitivity. Interestingly, we also observe that CISS can counter the deleterious effect of dipolar interaction and increase system sensitivity. The analysis has been performed for the toy model (only one nucleus) and a more general case where we consider up to six nuclei from the cryptochrome radical pair system. We observe that the CISS allows the radical pair model to have more realistic recombination rates with good sensitivity. We also do an analysis of the functional window of the avian compass reported in behavioral experiments in the functional window. We could not find a parameter set where a functional window can be observed along with CISS. We also show the effect of spin relaxation on the system and show that under relaxation, CISS shows increased compass sensitivity compared to no CISS case.

Automated summary

In this study, the researchers investigated the impact of chiral-induced spin selectivity (CISS) on the radical pair mechanism of avian magnetoreception. They found that CISS significantly increased the sensitivity of the avian compass and counteracted the deleterious effect of the dipolar interaction. The analysis showed that CISS allowed the radical pair model to have more realistic recombination rates and better sensitivity. Additionally, the researchers observed that spin relaxation further enhanced the compass sensitivity under CISS compared to the no CISS case.