Reactant-Product Quantum Coherence in Electron Transfer Reactions

TL;DR

This paper explores the nature of quantum superpositions between reactants and products in electron transfer reactions, showing they are suppressed due to intermediate states, with implications for quantum dynamics in spin-selective reactions.

Contribution

It clarifies the physical meaning of reactant-product superpositions and demonstrates their suppression in electron transfer, providing an intuitive Feynman diagram explanation.

Findings

Superpositions are strongly suppressed in electron transfer.

Intermediate states prevent the formation of reactant-product superpositions.

Implications for understanding quantum dynamics in radical-ion-pair reactions.

Abstract

We investigate the physical meaning of quantum superposition states between reactants and products in electron transfer reactions. We show that such superpositions are strongly suppressed and to leading orders of perturbation theory do not pertain in electron transfer reactions. This is because of the intermediate manifold of states separating the reactants from the products. We provide an intuitive description of these considerations with Feynman diagrams. We also discuss the relation of such quantum coherences to understanding the fundamental quantum dynamics of spin-selective radical-ion-pair reactions.