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Zeno is pro Darwin: Quantum Zeno Effect Suppresses the Dependence of Radical-Ion-Pair Reaction Yields on Exchange and Dipolar Interactions

Author: I. K. Kominis

Abstract: A biochemical quantum sensor of magnetic fields, namely magnetic-sensitive radical-ion-pair reactions, is understood to underlie avian magnetic navigation. It has been recently postulated [O. Efimova and P. J. Hore, Biophys. J. {\bf 94}, 1565 (2008)] that a fine-tuned cancellation of exchange and dipolar interactions in necessary for this magnetic sensor to function at earth's field. We here show that if the basic parameters of the radical-ion-pair are such that the quantum Zeno effect is manifested, the dependence of the magnetic-sensitive reaction yields on molecule-specific exchange and dipolar interactions is almost entirely suppressed. A fundamental quantum effect is thus shown to provide for the robustness of this biochemical sensor.