Reaction operators for spin-selective chemical reactions of radical pairs

TL;DR

This paper unifies traditional and recent quantum measurement models of spin-selective radical pair reactions into a comprehensive framework, enhancing understanding of their quantum dynamics.

Contribution

It introduces a general reaction scheme that encompasses both phenomenological and quantum measurement-based models for radical pair reactions.

Findings

The two existing models are limiting cases of the new scheme.

The unified framework clarifies the quantum dynamics of spin-selective reactions.

Provides a basis for more accurate modeling of radical pair chemistry.

Abstract

Spin-selective reactions of radical pairs have traditionally been modelled theoretically by adding phenomenological rate equations to the quantum mechanical equation of motion of the radical pair spin density matrix. More recently an alternative set of rate expressions, based on a quantum measurement approach, has been suggested. Here we show how these two reaction operators can be seen as limiting cases of a more general reaction scheme.