Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland.
Phys Rev Lett. 2014 Mar 7;112(9):094102. doi: 10.1103/PhysRevLett.112.094102. Epub 2014 Mar 6.
Synchronization is a universal phenomenon that is important both in fundamental studies and in technical applications. Here we investigate synchronization in the simplest quantum-mechanical scenario possible, i.e., a quantum-mechanical self-sustained oscillator coupled to an external harmonic drive. Using the power spectrum we analyze synchronization in terms of frequency entrainment and frequency locking in close analogy to the classical case. We show that there is a steplike crossover to a synchronized state as a function of the driving strength. In contrast to the classical case, there is a finite threshold value in driving. Quantum noise reduces the synchronized region and leads to a deviation from strict frequency locking.
同步是一种普遍现象，无论是在基础研究还是技术应用中都非常重要。在这里，我们研究了在最简单的量子力学场景中可能出现的同步现象，即一个量子力学自持续振荡器与外部谐波驱动器的耦合。我们使用功率谱来分析同步现象，包括频率追踪和频率锁定，与经典情况非常相似。我们表明，随着驱动强度的增加，会出现一个阶跃式的转变到同步状态。与经典情况不同的是，存在一个有限的驱动阈值。量子噪声会减小同步区域，并导致与严格的频率锁定偏离。
