The Quantum Phase Of Mesoscopic Circuit Driven By A Classical Signal

In Nano-technology, Nanoelectronics is a most important field. The research on single electron phenomena and the relative instruments are two main components, which form an offset in the solid science and technology field, i.e., Single Electronics. To depict single electron phenomena in the relative tunnel completely, it is necessary to study the influence of external circuit on single electron process and their interaction. This paper mainly focus on the electron transferring phase properties of mesoscopic circuits with external sources. The results show: (1) When the external source is a classical dirac impulse one , because of the interaction between external source and mesoscopic circuit, especially because of the nonlinear effect of mesoscopic capacitors, there exist not only the squeezing effect but also the quantum collapse and revival effect in the mesoscopic circuit. Both current and charge ofthe mesoscopic circuit have squeezing effect appearing alternately. When |a| < 1, the tellingsquezing effect appears; the larger the coherent strength , the stronger the cllapse and revival effect; That means the coherent strength, |a|, plays an inportment role in the cllapse andrevival effect of current. (2) When the external source is a classical ac one, the geometric phase factor, LR, appears in mesoscopic LC or RLC circuit at any time during the evolution of the circuit for the interation of the external source and circuit system. The mutual-couple energy between the two sides of capacitance and the resistance of the circuit were also taken into account. In our conclusion, the quantum state , which dominate the dynamic property of the system and the time evolution operator of the mesoscopic circuit were both obtained. And after further analysis, the wave function of the mesoscopic RLC system will evolve from an arbitrary initial state to a generalized squeezed state. And the squeezing effect is not related with the external drive but with the parameter of circuit itself .(3) we investigate the geometric phase of a mesoscopic coupled circuit with alternating source, the analysis results indicate that the state of mesoscopic coupled circuit will evolve from initial state to two-mode squeezed state due to the external source.And the squeezing phenomenon come from the coupled-capacitor, the external driving force has no effects on the squeezing property of the mesoscopic coupled circuit. The quantum dynamic phase and geometric phase are also obtained. When the coupled circuit be changed into single mesoscopic circuit the state will evolve to one-mode squeezed state as the time lapses .