有限温度下介观串并联RLC电路的量子涨落

将介观串并联RLC电路等效成阻尼谐振子.并量子化，利用热场动力学理论研究了热真空态、热相干态、热压缩态下电流和电压的量子涨落．结果表明，支路电流电压的量子涨落不仅与电路器件的参数有关，而且与压缩因子及压缩角有关．还与环境温度有关．且由于电流焦耳热、环境温度和阻尼电阻的影响，涨落随环境温度升高而增大，随时间增加而衰减．这对微小电路的设计、电路量子噪声的抑制，具有十分重要的理论指导意义．

Quantum Fluctuations of Mesoscopic Series-parallel Connection RLC Circuit at a Finite Temperature

When the inelastic coherence length of the charge carrier reaches the Fermi wavelength,quantum effects in electronic devices and circuit should be taken into account.Due to the existence of finite environmental temperature and damped resistance,practical circuits are always working in damped thermal states at finite temperature.With the rapid development of nanotechnology and microeletronics,the quantum effects of mesoscopic circuit have become an active problem now.In this paper,mesoscopic series-parallel connection RLC circuit was quantized by the method of damped harmonic oscillator quantization.Quantum fluctuatioins of the current and voltage of each branch were studied by thermo-field dynamics(TFD) theory in thermal vacuum state,thermal coherent state and thermal squeezed state.The results show that the quantum fluctuations of the current and voltage of each branch are related to not only parameters of the circuit,but also squeezed coeficients,squeezed angle and envionmental temperature.Because of the existence of current Joule heat,environmental temperature and damped resistances,the fluctuations increase with the increasing of temperature and decay with time.The study of these quantum fluctuation is significant for the design of miniature circuits and the reduction of quantum noise.