Quantum coherence in ion channels: resonances, transport and verification

Alipasha Vaziri,Martin B Plenio

doi:10.1088/1367-2630/12/8/085001

Abstract

Recently it was demonstrated that long-lived quantum coherence exists during excitation energy transport in photosynthesis. It is a valid question up to which length, time and mass scales quantum coherence may extend, how one may detect this coherence and what, if any, role it plays in the dynamics of the system. Here we suggest that the selectivity filter of ion channels may exhibit quantum coherence, which might be relevant for the process of ion selectivity and conduction. We show that quantum resonances could provide an alternative approach to ultrafast two-dimensional (2D) spectroscopy to probe these quantum coherences. We demonstrate that the emergence of resonances in the conduction of ion channels that are modulated periodically by time-dependent external electric fields can serve as signatures of quantum coherence in such a system. Assessments of experimental feasibility and specific paths towards the experimental realization of such experiments are presented.

Highlights

It was demonstrated that long-lived quantum coherence exists during excitation energy transport in photosynthesis
For a long time it was assumed that these transport processes may be modelled accurately as classical random processes and the possible relevance of non-classical phenomena such as quantum coherence was mostly ignored
The transport in the photosynthetic complex or the reactions during the first steps in vision [4, 5] involve initiation and fast transfer of electronic excitation via an absorbed photon on the femtosecond time scale. Given that these systems have been evolutionary optimized to function at highest efficiencies, they might seem to naturally suggest themselves as areas to look for quantum coherence

Summary

Introduction

It was demonstrated that long-lived quantum coherence exists during excitation energy transport in photosynthesis. In some systems, such as in current-carrying polymers or in the selectivity filter the observation of resonances in transport rates may provide an alternative approach towards the verification of the existence of quantum coherence and a means for direct demonstration of its importance for the system dynamics.

Results

Conclusion