Quantum Squeezing Effects of a Non-dissipative MesoscopicCircuit with Coupled Inductors and Capacitors

The quantum fluctuations of the charge and current in a non-dissipative mesoscopic circuit with coupled inductors and capacitors are studied for the squeezed vacuum state. The influence of the phase angle upon the quantum fluctuations is discussed in particular. Our results indicate that when the circuit parameters remain constant and the phases θ of the two circuits are equal, the squeezing of the charge or its conjugate variable increases. When the difference of the two phases equals π, the squeezing will deteriorate. Therefore, if we want to decrease the quantum noise, we should not only control the amplitude r, but also control the phase θ carefully.