Quantum probe and design for a chemical compass with magnetic nanostructures

TL;DR

This paper proposes optimizing chemical compass sensitivity using magnetic nanostructures and gradient fields, enhancing biomimetic magnetic sensing and probing spin correlations in radical pair reactions.

Contribution

It introduces a novel design approach for chemical compasses using gradient magnetic fields from nanostructures, improving directional sensitivity and enabling new experimental probes.

Findings

Gradient fields significantly enhance compass sensitivity.

Design principles for hybrid metallic-organic chemical compasses.

Gradient fields can probe spin correlations in radical pair reactions.

Abstract

Magnetic fields as weak as Earth's may affect the outcome of certain photochemical reactions that go through a radical pair intermediate. When the reaction environment is anisotropic, this phenomenon can form the basis of a chemical compass and has been proposed as a mechanism for animal magnetoreception. Here, we demonstrate how to optimize the design of a chemical compass with a much better directional sensitivity simply by a gradient field, e.g. from a magnetic nanostructure. We propose an experimental test of these predictions, and suggest design principles for a hybrid metallic-organic chemical compass. In addition to the practical interest in designing a biomimetic weak magnetic field sensor, our result shows that gradient fields can server as powerful tools to probe spin correlations in radical pair reactions.