Quantum Zeno Effect Explains Magnetic-Sensitive Radical-Ion-Pair Reactions

TL;DR

This paper demonstrates that the quantum Zeno effect, derived from quantum measurement theory, explains magnetic-sensitive radical-ion-pair reactions, resolving discrepancies with previous phenomenological models and aligning with recent experimental data.

Contribution

It introduces a new density matrix equation based on quantum measurement theory that incorporates the quantum Zeno effect to explain radical-ion-pair reactions.

Findings

The new model explains experimental magnetic sensitivities.

It accounts for chemical yield changes in radical-ion reactions.

Previous phenomenological models are insufficient.

Abstract

Chemical reactions involving radical-ion pairs are ubiquitous in biology, since not only are they at the basis of the photosynthetic reaction chain, but are also assumed to underlie the biochemical magnetic compass used by avian species for navigation. Recent experiments with magnetic-sensitive radical-ion pair reactions provided strong evidence for the radical-ion-pair magnetoreception mechanism, verifying the expected magnetic sensitivities and chemical product yield changes. It is here shown that the theoretical description of radical-ion-pair reactions used since the 70's cannot explain the observed data, because it is based on phenomenological equations masking quantum coherence effects. The fundamental density matrix equation derived here from basic quantum measurement theory considerations naturally incorporates the quantum Zeno effect and readily explains recent experimental observations on low- and high-magnetic-field radical-ion-pair reactions.