标题： 鸟类指南针功能在生物磁场噪声下的鲁棒性 显示英文标题

标题： Robustness of the avian compass function described by radical pair model against biomagnetic noise

摘要： 在鸟类眼睛中可能存在的磁感应机制作为指南针，检测地磁场倾斜度以帮助它们迁徙。 该机制由一种称为自由基对（RP）模型的量子自旋模型进行建模。 该模型表明，关于地磁场倾斜度的信息通过RP的自旋选择性重组作为生化信号传递。 然而，作为一种在温暖且嘈杂的体内环境中运行的精细量子系统，RP模型可能会受到不可避免的环境噪声的影响。 在本研究中，我们开发了一个基于Lindblad型主方程的模型，该模型结合了环境磁噪声。 我们的模型包括生物组织类型和生物系统的温度作为参数，考虑了它们的影响。 数值计算的结果表明，RP模型的指南针功能对来自电磁场热涨落的内在磁噪声具有鲁棒性，在现实的生物磁范围内。 然而，远超过生物磁范围的环境磁场噪声，其量级为数百到数千$\mu$T，会显著影响并破坏指南针功能。 这项工作为量化生物环境中开放量子系统的环境影响提供了基础，并提供了一种将环境磁场的实验测量与量子噪声建模联系起来的工具。 显示英文摘要

摘要： The magnetic sensing mechanism proposed to exist in avian eyes functions as a compass that detects the geomagnetic inclination aiding their migration. This mechanism is modeled by a quantum spin model known as the radical pair (RP) model. This model suggests that information about geomagnetic inclination is transmitted as biochemical signals via spin-selective recombination of the RP. However, as a delicate quantum system in a warm and noisy in vivo environment, the RP model is likely to be subject to unavoidable environmental noise. In this study, we develop a model that incorporates environmental magnetic noise, based on a Lindblad-type master equation. Our model includes the type of biological tissue and the temperature of the biological system as parameters, accounting for their effects. The results of numerical calculations indicate that the compass function of the RP model is robust against intrinsic magnetic noise arising from thermal fluctuations in the electromagnetic field within realistic biomagnetic range. However, noise from an environmental magnetic field far exceeding the biological magnetic range, on the order of hundreds to thousands of $\mu$T, significantly affects and disrupts the compass function. This work provides a foundation for quantifying environmental influences on open quantum systems in biological settings and offers a tool for connecting experimental measurements of environmental magnetic fields with quantum noise modeling.