The quantum needle of the avian magnetic compass
The quantum needle of the avian magnetic compass
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DOI：
10.1073/pnas.1600341113
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发表时间：
2016-04-26
影响因子：
11.1
通讯作者：
Hore, P. J.
中科院分区：
文献类型：
--
作者：
Hiscock, Hamish G.;Worster, Susannah;Hore, P. J.
候鸟有一个依赖于光的磁罗盘，其机制被认为涉及视网膜中隐花色素蛋白质中光化学形成的自由基对。这种罗盘的理论描述至今无法解释鸟类能够高精度地探测地球磁场的方向。在这里，我们使用相干自旋动力学模拟来探索基于隐花色素的自由基对的现实模型的行为。我们表明，当自旋相干持续时间超过几微秒，传感器的输出包含一个尖锐的功能，称为尖峰。尖峰来自于隐花色素中形成的自由基的量子力学自旋能级的避免交叉。这样的特征可以提供足以解释野生候鸟导航行为的航向精度。我们的研究结果（一）提供了新的见解，以自由基对磁接收，（二）建议的方式，其中的性能的指南针可能已经被优化的进化，（三）可能会提供一个开始的解释磁迷失方向的候鸟暴露于人为电磁噪声，和（四）表明，自由基对磁接收可能是一个量子生物学现象比以前实现的。
Migratory birds have a light-dependent magnetic compass, the mechanism of which is thought to involve radical pairs formed photochemically in cryptochrome proteins in the retina. Theoretical descriptions of this compass have thus far been unable to account for the high precision with which birds are able to detect the direction of the Earth's magnetic field. Here we use coherent spin dynamics simulations to explore the behavior of realistic models of cryptochrome-based radical pairs. We show that when the spin coherence persists for longer than a few microseconds, the output of the sensor contains a sharp feature, referred to as a spike. The spike arises from avoided crossings of the quantum mechanical spin energy-levels of radicals formed in cryptochromes. Such a feature could deliver a heading precision sufficient to explain the navigational behavior of migratory birds in the wild. Our results (i) afford new insights into radical pair magneto-reception, (ii) suggest ways in which the performance of the compass could have been optimized by evolution, (iii) may provide the beginnings of an explanation for the magnetic disorientation of migratory birds exposed to anthropogenic electromagnetic noise, and (iv) suggest that radical pair magnetoreception may be more of a quantum biology phenomenon than previously realized.