介观电路压缩态的热动力学研究

利用信息理论和密度矩阵，分析研究了频率随时间变化的介观LC电路中的相干态及压缩态。通过与密度矩阵相关算符，我们将相干态、压缩态的出现与电路的初始条件联系起来。结果显示：系统量子态的演化和初始状态密切相关。一般来说，由于环境温度的影响，初始处于某一激发态的介观LC电路系统会演化到压缩态；在低温下，让电路参数作阶跃变化，如果跃变前后电路的谐振频率不变，则能够制备出压缩最小测不准态。

Thermodynamics of squeezed states in mesoscopic circuits

Based on information theory, we present a density matrix to discuss coherent and squeezed states for a mesoscopic LC circuit with time-dependent frequency. With the relevant operators included in the density matrix, a connection between the appearance of coherent and squeezed states is established, i.e., the quantum state evolution of system is highly relevant to the initial state. Generally speaking, due to the effect of circumstance temperature, mesoscopic LC circuit will evolve to squeezed state when it initially lies in an excited state. In particular, at a low temperature, step changes of circuit parameters will result in the squeezed minimum uncertainty state if the resonance frequency remains consistent after the change.