Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
Sci Rep. 2022 Apr 9;12(1):6011. doi: 10.1038/s41598-022-09901-7.
It is hypothesised that the avian compass relies on spin dynamics in a recombining radical pair. Quantum coherence has been suggested as a resource to this process that nature may utilise to achieve increased compass sensitivity. To date, the true functional role of coherence in these natural systems has remained speculative, lacking insights from sufficiently complex models. Here, we investigate realistically large radical pair models with up to 21 nuclear spins, inspired by the putative magnetosensory protein cryptochrome. By varying relative radical orientations, we reveal correlations of several coherence measures with compass fidelity. Whilst electronic coherence is found to be an ineffective predictor of compass sensitivity, a robust correlation of compass sensitivity and a global coherence measure is established. The results demonstrate the importance of realistic models, and appropriate choice of coherence measure, in elucidating the quantum nature of the avian compass.
据推测，鸟类的罗盘依赖于重组自由基对中的自旋动力学。已经有人提出，量子相干性是这一过程的一种资源，大自然可能会利用这种资源来提高罗盘的灵敏度。迄今为止，相干性在这些自然系统中的真正功能作用仍然是推测性的，缺乏足够复杂的模型所提供的见解。在这里，我们研究了受假定的磁敏蛋白隐花色素启发的最大可达 21 个核自旋的实际大型自由基对模型。通过改变相对自由基取向，我们揭示了几个相干性度量与罗盘保真度的相关性。虽然电子相干性被发现是罗盘灵敏度的无效预测指标，但我们确立了罗盘灵敏度和全局相干性度量之间的稳健相关性。研究结果表明，在阐明鸟类罗盘的量子性质方面，逼真的模型和相干性度量的适当选择非常重要。
