Lamb shift in radical-ion pairs produces a singlet-triplet energy splitting in photosynthetic reaction centers

Abstract

Radical-ion pairs, fundamental for understanding photosynthesis and the avian magnetic compass, were recently shown to be biological open quantum systems. We here show that the coupling of the radical-pair's spin degrees of freedom to its decohering vibrational reservoir leads to a shift of the radical-pair's magnetic energy levels. The Lamb shift Hamiltonian is diagonal in the singlet-triplet basis, and results in a singlet-triplet energy splitting physically indistinguishable from an exchange interaction. This could have significant implications for understanding the energy level structure and the dynamics of photosynthetic reaction centers.

7 pages, 2 figures

References in corpus (2)

• Introduction to decoherence theory
• Spin-selective reactions of radical pairs act as quantum measurements

Cited by in corpus (4)

• Spin-selective electron transfer reactions of radical pairs: beyond the Haberkorn master equation
• The radical-pair mechanism as a paradigm for the emerging science of quantum biology
• Quantum-limited biochemical magnetometers designed using the Fisher information and quantum reaction control
• Quantum Information Processing in the Radical-Pair Mechanism: Haberkorn theory violates the Ozawa entropy bound