Entanglement and Sources of Magnetic Anisotropy in Radical Pair-Based Avian Magnetoreceptors

TL;DR

This paper explores how quantum entanglement and magnetic anisotropy in radical pairs influence the sensitivity and directional response of avian magnetoreception, suggesting new design principles for magnetic sensors.

Contribution

It introduces the role of electron spin entanglement and triplet anisotropy in enhancing the sensitivity of radical pair-based magnetic sensors.

Findings

Radical pairs from spin-polarized triplets can improve compass sensitivity.

Entanglement influences the directional response of the magnetoreceptor.

Triplet anisotropy offers a new mechanism for magnetic sensing.

Abstract

One of the principal models of magnetic sensing in migratory birds rests on the quantum spin-dynamics of transient radical pairs created photochemically in ocular cryptochrome proteins. We consider here the role of electron spin entanglement and coherence in determining the sensitivity of a radical pair-based geomagnetic compass and the origins of the directional response. It emerges that the anisotropy of radical pairs formed from spin-polarized molecular triplets could form the basis of a more sensitive compass sensor than one founded on the conventional hyperfine-anisotropy model. This property offers new and more flexible opportunities for the design of biologically inspired magnetic compass sensors.