共查询到20条相似文献,搜索用时 31 毫秒
1.
Under the Born-von-Karmann periodic boundary condition, we
propose a quantization scheme for non-dissipative distributed parameter
circuits (i.e. a uniform periodic transmission line). We find the unitary
operator for diagonalizing the Hamiltonian of the uniform periodic
transmission line. The unitary operator is expressed in a coordinate
representation that brings convenience to deriving the density matrix
ρ(q,q',β). The quantum fluctuations of charge and current at a definite temperature have been studied. It is shown that quantum fluctuations of distributed parameter circuits, which also have distributed
properties, are related to both the circuit parameters and the positions and
the mode of signals and temperature T. The higher the temperature
is, the stronger quantum noise the circuit exhibits. 相似文献
2.
Xing-Lei Xu Hong-Qi Li Ji-Suo Wang 《International Journal of Theoretical Physics》2006,45(12):2471-2482
Mesoscopic damped double resonance mutual capacitance coupled RLC circuit is quantized by the method of damped harmonic oscillator quantization. The Hamiltonian is diagonalized by unitary transformation. The eigenenergy spectra of this circuit are given. The quantum fluctuations of the charges and current of each loop are researched in excitation state of the squeezed vacuum state, the squeezed vacuum state and in vacuum state. It is show that, the quantum fluctuations of the charges and current are related to not only circuit inherent parameter and coupled magnitude, but also quantum number of excitation, squeezed coefficients, squeezed angle and damped resistance. And, because of damped resistance, the quantum fluctuation decay along with time.
PACS numbers: 03.65.-w,42.50.Lc. 相似文献
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QUANTUM FLUCTUATIONS IN A MESOSCOPIC DAMPED LC PARALLEL CIRCUIT IN DISPLACED SQUEEZED FOCK STATE 总被引:3,自引:0,他引:3 下载免费PDF全文
We study the quantum effects of a damped LC parallel circuit considering its different performance from an RLC series circuit in classical physics. The damped LC parallel circuit with a source is quantized and the quantum fluctuations of magnetic flux and electric charge in the circuit in displaced squeezed Fock state are investigated. It is shown that, as in the RLC series circuit, the fluctuations only depend on the squeezing parameter and the parameters of the circuit components in the damped LC parallel circuit, but the effects of the circuit components on the fluctuations are different in the two circuits. 相似文献
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Double-wave description of mesoscopic resistance-inductance-capacitance coupled circuit with power source 下载免费PDF全文
Quantum fluctuations in the mesoscopic capacitance-inductance-resistance coupled circuit with a power source are investigated using canonical transformation and a double wavefunction. We confirm that the fluctuations are not influenced by the power source. As a new method, the double wavefunction describes a single system of the coupled circuit, whereas the single wavefunction describes a quantum ensemble. 相似文献
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介观串并联RLC电路的量子涨落 总被引:4,自引:0,他引:4
借鉴阻尼谐振子的量子力学处理的研究思想,将介观RLC串并联电路量子化.在此基础上,研究了真空态下各支路电流和电压的量子涨落.结果表明,各支路电流电压的量子涨落均与电路器件的参数有关,且随时间衰减. 相似文献
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介观耗散LC并联电路的量子效应 总被引:10,自引:1,他引:9
对介观耗散LC并联电路作阻尼谐振子处理,将其量子化。在此基础上,研究了Fock态及压缩真空态下,介观耗散LC并联电路中各支路电流和电压的量子涨落。结果表明,各支路电流电压的量子涨落均与电路器件的固有参数及所选量子态有关。 相似文献
9.
Quantum fluctuations of mesoscopic damped double resonance RLC circuit with mutual capacitance--inductance coupling in thermal excitation state 总被引:7,自引:0,他引:7 下载免费PDF全文
Based on the scheme of damped harmonic oscillator quantization and
thermo-field dynamics (TFD), the quantization of mesoscopic damped
double resonance RLC circuit with mutual capacitance--inductance
coupling is proposed. The quantum fluctuations of charge and current
of each loop in a
squeezed vacuum state are studied in the thermal excitation case. It is shown
that the fluctuations not only depend on circuit inherent parameters,
but also rely on excitation quantum number and squeezing parameter.
Moreover, due to the finite environmental temperature and
damped resistance, the fluctuations increase with the temperature rising,
and decay with time. 相似文献
10.
压缩角对介观耦合电压缩效应的影响 总被引:3,自引:0,他引:3
从无耗散的电感耦合是电路的经典运动方程出发,研究了压缩真空态下介观电感耦合电路中电荷和电流的量子涨落;着重分析了压缩幅角参数对电荷和电流量子压缩效应的影响,结果表明:在任意幅角θ下,电荷或电流的量子涨落不是随压缩参数r增加而单调地减小,而是存在着一个极小值。 相似文献
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Quantum Fluctuations of Current and Voltage for Mesoscopic Quartz Piezoelectric Crystal at Finite Temperature 下载免费PDF全文
The mesoscopic quartz piezoelectric crystal equivalent circuit is quantized by the method of damped harmonic oscillator quantization. It is shown that the quantum fluctuations of voltage and current of each loop are related to not only the equivalent circuit inherent parameter and squeezing parameter, but also the temperature, and decay according to exponent along with time in the thermal vacuum state, the thermal coherent state and the thermal squeezed state. 相似文献
13.
利用C-V(电容-电压)变换器及V-T(电压-时间)变换器设计了一种电容参数的数字化测量电路,并进一步阐述了电容参数的数字化测量原理. 相似文献
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从耗散传输线的经典运动方程出发,将传输线中的单模信号进行量子化,研究了传输线在激发相干态下的量子效应.结果表明,传输线的量子涨落不仅与电路参数和电路的状态有关,还与传输线的位置有关.
关键词:
介观传输线
耗散
单模
激发相干态 相似文献
17.
We study the quantum fluctuations of the charge and current of two L-C dissipative mcsoscopic circuit withthe mutual inductance in the vacuum state. Our results show that the system state will evolve to a squerzcd coherentstate under the effect of external source. We find that the squeezing amplitude parameter is relative to the parametersof circuit and the mutual-inductance coefficient in the existence of dissipation. Whcn the circuit has no dissipation orthere is complete coupling between two meshes, the squeezing amplitude parameter only depends on the capacitance'sratio. 相似文献
18.
We study the quantum fluctuations of the charge and current of two L-C dissipative mesoscopic circuit with the mutual inductance in the vacuum state.Our results show that the system state will evolve to a squeezed coherent state under the effect of external source.We find that the squeezing amplitude parameter is relative to the parameters of circuit and the mutual-inductance coefficient in the existence of dissipation.When the circuit has no dissipation or there is complete coupling between two meshes,the squeezing amplitude parameter only depends on the capacitance‘s ratio. 相似文献
19.
Critical phenomena in distributed dynamical two-dimensional nonlinear system near the point of the Turing instability are discussed. The system is considered in the presence of thermal fluctuations and multiplicative noise (MN) representing fluctuations of the bifurcation parameter. Since such a noise of the control parameter can have macroscopic (not thermal) nature, the intensity is considered as sufficiently large in comparison with the amplitude of thermal fluctuations, and it is shown that in the system the first order phase transition occurs with the characteristics which are independent on the thermal noise. Hence the discontinuous transtion could be observable in experimental situations where this would not be possible in the absence of MN (like the Rayleigh-Benard problem). When the correlation length of MN is small, the transition results in the formation of a complex state possessing only short-range order, and when MN is spatially uniform, a quasi-one-dimensional structure will be formed. 相似文献
20.
The Quantum Fluctuations of Two Coupled Josephson Junctions with the Discreteness of Electric Charge
De-Xin Miao Ju-Ju Hu Ying-Hua Ji Shu-Qin Liu 《International Journal of Theoretical Physics》2007,46(11):2808-2815
The quantization of two Josephson junctions coupled via inductor with the discreteness of electric charges is proposed. The
finite-difference Schrodinger equation of the circuit system has been obtained in charge representation, and the Schrodinger
equation is turned to be Mathieu equation in flux representation. The wavefunction and energy spectrum can be solved by adopting
the canonical transformation and unitary transformation method. The results indicate that the quantum fluctuations of the
flux in the ground states of each mesh exist and are interrelated. 相似文献