论文标题
时钟的热力学
The thermodynamics of clocks
论文作者
论文摘要
所有时钟，经典或量子，都是受热力学限制的开放式非平衡不可逆系统。使用示例我表明，这些约束必然限制了时钟的性能，并且良好的时钟需要大量的能量耗散。对于周期性时钟，在极限周期中运行，这是相扩散的结果。对于非周期性时钟（例如，无线电碳年代定年）也是如此，但由于电报噪声而不是相扩散。在这种情况下，通过降低熵的准确测量值，从而提高了时钟的自由能，并需要进入低熵储层，从而发挥关键作用。在量子情况下，热噪声被量子噪声（自发发射或隧道）取代，测量对于周期性和非周期性时钟都起着至关重要的作用。本文以讨论托尔曼关系和rovelli的热时间假设的讨论结尾。
All clocks, classical or quantum, are open non equilibrium irreversible systems subject to the constraints of thermodynamics. Using examples I show that these constraints necessarily limit the performance of clocks and that good clocks require large energy dissipation. For periodic clocks, operating on a limit cycle, this is a consequence of phase diffusion. It is also true for non periodic clocks (for example, radio carbon dating) but due to telegraph noise not to phase diffusion. In this case a key role is played by accurate measurements that decrease entropy, thereby raising the free energy of the clock, and requires access to a low entropy reservoir. In the quantum case, for which thermal noise is replaced by quantum noise (spontaneous emission or tunnelling), measurement plays an essential role for both periodic and non periodic clocks. The paper concludes with a discussion of the Tolman relations and Rovelli's thermal time hypothesis in terms of clock thermodynamics.
