Quantum limit for avian magnetoreception: How sensitive can a chemical compass be?

TL;DR

This paper explores the quantum limits of avian chemical compasses, showing how quantum coherence and control can enhance sensitivity, and suggests pathways for designing biomimetic magnetic sensors.

Contribution

It identifies optimal hyperfine couplings and demonstrates that quantum control and decoherence can improve chemical compass sensitivity.

Findings

Quantum coherence can be exploited to enhance sensitivity.

Simple quantum control extends the magnetic sensitivity limit.

Decoherence may have a beneficial role in compass function.

Abstract

The chemical compass model, based on radical pair reactions, is a fascinating idea to explain avian magnetoreception. At present, questions concerning the key ingredients responsible for the high sensitivity of a chemical compass and the possible role of quantum coherence and decoherence remain unsolved. Here, we investigate the optimized hyperfine coupling for a chemical compass in order to achieve the best magnetic field sensitivity. We show that its magnetic sensitivity limit can be further extended by simple quantum control and may benefit from additional decoherence. With this, we clearly demonstrate how quantum coherence can be exploited in the functioning of a chemical compass. The present results also provide new routes towards the design of a biomimetic weak magnetic field sensor.