Thermodynamics of squeezed states in mesoscopic circuits
介观电路压缩态的热动力学研究

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.