Squeezed Effect And Coulomb Blockade Effect In Mesoscopic Circuit

In this paper, the theoretical deductions and numerical analysis of mesoscopic circuit with mesoscopic capacitance are presented. The studies contain the quantum squeezing effect in the mesoscopic LC circuit and the Coulomb blockade effect in the mesoscopic capacitance coupling RLC circuit.In chapter 3, from the viewpoint that the electron wave function of the two polar plates in the mesoscopic capacitance is coupled, we take the coupling energy into account and obtain the Hamilton of the mesoscopic LC circuit without electromotive force. Subsequently, we study the evolution of the quantum state, the quantum squeezing effects of the charge and the current, and the quantum CR phenomenon of the tunneling current in the capacitance. The results show that there exists quantum squeezing effects not only on the charge but also on the conjugated current, and that the two conjugates' quantum squeezing effects alternately assume periodicity. On the condition of |β|<1, the squeezing effects are more evident. The quantum CR phenomenon appears obvious with the increase of the |β|, but the Ω/ω only affects the oscillation in the time of periods.In chapter 4, regarding the discreteness of electric charge, we present the method of the mesoscopic capacitance coupling RLC circuit and studied the Coulomb blockade effect in the circuit. Our results indicate that the adiabatic approximation electromotive force only takes discrete values, and there exists a threshold voltage. When the electromotive force is less than the threshold voltage, the electric current in the mesoscopic capacitance is zero by reason of the Coulomb force. It is the coulomb blockade effect. Secondly, the effects of electric parameter to the threshold voltage are discussed by numerical simulation. We find that the condition for Coulomb blockade is related not only to the junction capacitance, but also to the inductance and resistance, and the effect of the coupling capacitance to the threshold voltage exists welter. Finally, the quantum fluctuation of the mesoscopic circuit is also studied.