介观电路的量子效应

本用涨落耗散定理证明了一个有源ＲＬＣ电路,在温度接近绝对零度时,存在量子效应;而当温度升高时,这一量子效应被热力学涨落淹没,并给出了绝对零度时,该电路的量子噪声的大小,以及电荷,电流的测不准点系。     

耗散介观电容耦合电路的量子效应

对介观耗散电容耦合电路作阻尼谐振子处理,将其量子化,在此基础上研究电荷和电流在能量本征态下的量子涨落,并对其进行讨论.结果表明,每个回路的电荷、电流都存在量子涨落,且两回路的量子噪声是相互关联的.关键词：介观耗散电路电容耦合量子涨落     

介观电容耦合电路的量子涨落

从无耗散的电容耦合电路的经典运动方程出发,分别研究了这一耦合电路在任一本征态下和在压缩真空态下电荷、电流的量子涨落.结果表明,两个回路中的量子噪声是相互关联的.关键词：     

无耗散介观电感耦合电路的量子效应

本文从无耗散的电感耦合电路的经典运动方程出发,分别研究了这一耦合电路在其任意的本征态下和压缩真空态下电路中电荷、电流的量子涨落,其结果表明,每个回路中的电荷、电流都存在着量子涨落,且两回路中的量子噪音是相互关联的。     

压缩真空态的激发态下介观耦合电路的量子效应

通过量子化电容耦合电路和对角化电路哈密顿量,研究了介观电路在压缩真空态的激发态下的量子力学效应.     

嵌入并联耦合双量子点介观环系统中的近藤效应

使用双杂质Anderson模型的哈密顿,从理论上研究了一个嵌入并联耦合双量子点介观环系统 , 当处在Kondo区时的基态性质, 并用slave-boson平均场方法求解了哈密顿.研究的结果表 明, 在这个系统中,当两个量子点处于强耦合时,两个量子点可以相干耦合成一个人造分 子,导致一个增强的Kondo效应和超强持续电流的出现.因此,在未来的纳米装置应用中,这 个系统具有潜在的应用价值. 关键词：并联耦合双量子点Kondo效应超强持续电流     

介观RLC并联电路量子效应

研究了介观RLC并联电路系统量子态随时间的演化，结果表明，在外加电源作用下，有耗散的RLC并联电路，系统将由初始的真空态演化到压缩态。     

嵌入耦合量子点的介观Aharonov-Bohm环内的持续电流

使用双杂质的Anderson模型的哈密顿量,从理论上研究了一个嵌入耦合量子点的介观Aharonov-Bohm环系统处在Kondo区时的基态性质, 并用slave-boson平均场方法求解了哈密顿量. 结果表明, 在这个系统中, 宇称效应和复杂的电流 相位关系的出现反映了两个量子点可以相干耦合.关键词：持续电流耦合量子点宇称效应Kondo效应     

交变电源作用下介观电感耦合电路中电荷与电流的量子涨落

利用量子厄米不变量理论,我们研究了交变电源作用下介观电感耦合电路的量子动力学,不仅得到了含时薛定谔方程的精确解,计算了电路中电荷与电流的量子涨落,同时也得到了介观电路的非绝热非循环几何相位的表达式.     

介观RLC电路的量子效应

将介观电容器看作介观隧道结,对介观RLC电路作了相应的量子力学处理.研究了介观RLC电路系统的量子态演化.研究表明:考虑介观电容耦合效应的影响,介观RLC电路系统将由初始的Fock态演化到压缩Fock态,并讨论了电荷及磁通在压缩Fock态下的量子涨落.     

Quantum Effect in Mesoscopic Open Electron Resonator

The open electron resonator is a mesoscopic device that has attracted considerable attention due to its remarkable behavior： conductance oscillations. In this paper, using an improved quantum theory to mesoscopic circuits developed recently by Li and Chen, the mesoscopic electron resonator is quantized based on the fundamental fact that the electric charge takes discrete value. With presentation transformation and unitary transformation, the SchrSdinger equation becomes an standard Mathieu equation. Then, the detailed energy spectrum and wave functions in the system axe obtained, which will be helpful to the observation of other characters of electron resonator. The average of currents and square of the current are calculated, the results show the existence of the current fluctuation, which causes the noise in the circuits, the influence of inductance to the noise is discussed. With the results achieved, the stability characters of mesoscopic electron resonator are studied firstly, these works would be benefit to the design and control of integrate circuit.     

Quantum Effect in the Mesoscopic RLC Circuits with a Source

The research work on the quantum effects in mesoscopic circuits has undergone a rapid development recently, however the whole quantum theory of the mesoscopic circuits should consider the discreteness of the electric charge. In this paper, based on the fundamental fact that the electric charge takes discrete values, the finite-difference Schrodinger equation of the mesoscopic RLC circuit with a source is achieved. With a unitary transformation, the Schrodinger equation becomes the standard Mathieu equation, then the energy spectrum and the wave functions of the system are obtained. Using the WKBJ method, the average of durrents and square of the current are calculated. The results show the existence of the current fluctuation, which causes noise in the circuits. This paper is an application of the whole quantum mesoscopic circuits theory to the fundamental circuits, and the results will shed light on the design of the miniation circuits, especially on the purpose of reducing quantum noise coherent controlling of the mesoscopic quantum states.     

Quantum Effect in the Mesoscopic RLC Circuits with a Source

The research work on the quantum effects in mesoscopic circuits has undergone a rapid development recently, however the whole quantum theory of the mesoscopic circuits should consider the discreteness of the electric charge. In this paper, based on the fundamental fact that the electric charge takes discrete values, the finite-difference Schrodinger equation of.the mesoscopic RLC circuit with a source is achieved. With a unitary transformation, the Schrodinger equation becomes the standard Mathieu equation, then the energy spectrum and the wave functions of the system are obtained. Using the WKBJ method, the average of currents and square of the current are calculated. The results show the existence of the current fluctuation, which causes noise in the circuits. This paper is an application of the whole quantum mesoscopic circuits theory to the fundamental circuits, and the results will shed light on the design of the miniation circuits, especially on the purpose of reducing quantum noise coherent controlling of the mesoscopic quantum states.     

Quantum Fluctuation of a Mesoscopic Inductance Coupling Circuit at Finite Temperature

We study the quantization of mesoscopic inductance coupling circuit and discuss its time evolution. Bymeans of the thermal field dynamics theory we study the quantum fluctuation of the system at finite temperature.     

The Squeezing Effect in a Mesoscopic RLC Circuit

Using the path integral method we derive quantum wave function and quantum fluctuations of charge andcurrent in the mesoscopic RLC circuit. We find that the quantum fluctuation of charge decreases with time, oppositely,the quantum fluctuation of current increases with time monotonously. Therefore there is a squeezing effect in the circuit.If some more charge devices are used in the mesoscopic-damped circuit, the quantum noise can be reduced. We also findthat uncertainty relation of charge and current periodically varies with the period π/2 in the under-damped case.     

Quantum Effect in a Diode Included Nonlinear Inductance-Capacitance Mesoscopic Circuit

The mesoscopic nonlinear inductance-capacitance circuit is a typical anharmonie oscillator, due to diodes included in the circuit. In this paper, using the advanced quantum theory of mesoseopie circuits, which based on the fundamental fact that the electric charge takes discrete value, the diode included mesoscopic circuit is firstly studied. Schrodinger equation of the system is a four-order difference equation in p rep asentation. Using the extended perturbative method, the detail energy spectrum and wave functions axe obtained and verified, as an application of the results, the current quantum fluctuation in the ground state is calculated. Diode is a basis component in a circuit, its quantization would popularize the quantum theory of mesoscopie circuits. The methods to solve the high order difference equation are helpful to the application of mesoscopic quantum theory.     

Nonzero Temperature Squeezing of the Time—Dependent Harmonic Oscillator and the Applications to the Capacitive Coupled Electric Circuit

A new way to calculate the nonzero temperature quantum fluctuations of the time-dependent harmonic oscillator is proposed and the properties of squeezing are exactly given.The method is applied to the capacitive coupled electric circuit.It is explicitly shown that squeezing can appear and the squeezing parameters are related to the physical quantities of the coupled circuit.