Driven spin dynamics enhances cryptochrome magnetoreception: Towards live quantum sensing

TL;DR

This paper shows that driving the spin dynamics in cryptochrome radical pairs via modulation of inter-radical distance significantly enhances geomagnetic field sensitivity, advancing understanding of magnetoreception mechanisms.

Contribution

It introduces a novel dynamical approach to overcome inter-radical interaction limitations, improving magnetoreception sensitivity through a Landau-Zener transition.

Findings

Dynamical modulation enhances geomagnetic sensitivity in radical pairs.

Landau-Zener transition facilitates spin state conversion under driving.

Driven systems outperform static counterparts in sensitivity.

Abstract

The mechanism underlying magnetoreception has long eluded explanation. A popular hypothesis attributes this sense to the quantum coherent spin dynamics of spin-selective recombination reactions of radical pairs in the protein cryptochrome. However, concerns about the validity of the hypothesis have been raised as unavoidable inter-radical interactions, such as strong electron-electron dipolar coupling, appear to suppress its sensitivity. We demonstrate that this can be overcome by driving the spin system through a modulation of the inter-radical distance. It is shown that this dynamical process markedly enhances geomagnetic field sensitivity in strongly coupled radical pairs via a Landau-Zener type transition between singlet and triplet states. These findings suggest that a "live" harmonically driven magnetoreceptor can be more sensitive than its "dead" static counterpart.