FLUCTUATIONS AT FINITE TEMPERATURE AND THERMODYNAMICS OF MESOSCOPIC RLC CIRCUIT CALCULATED BY USING GENERALIZED THERMAL VACUUM STATE

2011 ◽  
Vol 25 (31) ◽  
pp. 2353-2361 ◽  
Author(s):  
HONG-CHUN YUAN ◽  
XUE-XIANG XU ◽  
XUE-FEN XU ◽  
HONG-YI FAN
Keyword(s):  
Thermal Field ◽  
Quantum Noise ◽  
Vacuum State ◽  
Nonzero Temperature ◽  
Thermal Vacuum ◽  
Partial Trace ◽  
Expectation Value ◽  
Rlc Circuit ◽  
Thermal Vacuum State ◽  
Mesoscopic Rlc Circuit

By using the partial trace method and the technique of integration within an ordered product of operators we obtain the explicit expression of the generalized thermal vacuum state (GTVS) for an RLC circuit instead of using the Takahashi–Umezawa approach. According to thermal field dynamics (TFD), namely, the expectation value of physical observables in this GTVS is equivalent to their ensemble average, based on GTVS we successfully derive the quantum fluctuations at nonzero temperature and the thermodynamical relations for the mesoscopic RLC circuit. Our results show that the higher the temperature is, the more quantum noise the RLC circuit exhibits.

QUANTUM FLUCTUATION IN THERMAL VACUUM STATE FOR MESOSCOPIC DISTRIBUTED PARAMETER CIRCUITS

2005 ◽  
Vol 19 (10) ◽  
pp. 1731-1740 ◽  
Author(s):  
YING-HUA JI ◽  
HAI-MEI LUO ◽  
YI-FAN WANG ◽  
JIAN-MO WANG
Keyword(s):  
Thermal Field ◽  
Unitary Operator ◽  
Quantum Noise ◽  
Quantum Fluctuation ◽  
Vacuum State ◽  
Distributed Parameter ◽  
Thermal Vacuum ◽  
Distributed Parameter Circuit ◽  
Field Dynamic ◽  
Periodic Transmission

In this paper we consider a non-dissipative distributed parameter circuit at a finite temperature T. We find the unitary operator for diagonalizing the Hamiltonian of the uniform periodic transmission line. The unitary operator is expressed in a coordinate representation. Thermal field dynamic is used in our discussion. It is shown that distributing parameter circuits and quantum fluctuations, which also have distributing properties, are related to both the circuit parameters and the positions and the model of signals and temperature T. The higher the temperature, the more quantum noise the circuit exhibits. The research will be helpful to miniaturize intergreate circuits and electric components. It will be also significant for the futher study of the qualitities of mesoscopic system.

Quantum Fluctuation in Thermal Vacuum State for Nondissipative Mesoscopic Capacitance Coupling Circuit

2003 ◽  
Vol 17 (15) ◽  
pp. 821-828
Author(s):  
Tong-Qiang Song
Keyword(s):  
Finite Temperature ◽  
Thermal Field ◽  
Quantum Fluctuation ◽  
Vacuum State ◽  
Thermal Vacuum ◽  
Coupling Circuit ◽  
Thermal Vacuum State ◽  
Capacitance Coupling

By means of the thermal field dynamics (TDF) theory we study the quantum fluctuation of a nondissipative mesoscopic capacitance coupling circuit at a finite temperature.

scholarly journals Proposal of a Computational Approach for Simulating Thermal Bosonic Fields in Phase Space

Physics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 402-411 ◽  
Author(s):  
Alessandro Sergi ◽  
Roberto Grimaudo ◽  
Gabriel Hanna ◽  
Antonino Messina
Keyword(s):  
Phase Space ◽  
Thermal Noise ◽  
Fock Space ◽  
Vacuum State ◽  
Thermal Bath ◽  
Wigner Transform ◽  
Thermal Vacuum ◽  
Thermo Field Dynamics ◽  
Augmented Space ◽  
Thermal Vacuum State

When a quantum field is in contact with a thermal bath, the vacuum state of the field may be generalized to a thermal vacuum state, which takes into account the thermal noise. In thermo field dynamics, this is realized by doubling the dimensionality of the Fock space of the system. Interestingly, the representation of thermal noise by means of an augmented space is also found in a distinctly different approach based on the Wigner transform of both the field operators and density matrix, which we pursue here. Specifically, the thermal noise is introduced by augmenting the classical-like Wigner phase space by means of Nosé–Hoover chain thermostats, which can be readily simulated on a computer. In this paper, we illustrate how this may be achieved and discuss how non-equilibrium quantum thermal distributions of the field modes can be numerically simulated.

PARASTATISTICAL SYSTEMS AT FINITE TEMPERATURES IN THERMOFIELD DYNAMICS

1992 ◽  
Vol 07 (16) ◽  
pp. 3807-3816
Author(s):  
P. SHANTA ◽  
S. CHATURVEDI ◽  
A.K. KAPOOR ◽  
V. SRINIVASAN
Keyword(s):  
Single Mode ◽  
Vacuum State ◽  
Zero Temperature ◽  
Thermal Vacuum ◽  
Nonlinear Realization ◽  
Thermal Vacuum State

We consider para-Bose and para-Fermi oscillators within the framework of thermofield dynamics. For these systems, we construct the transformation relating the thermal vacuum state to the zero temperature vacuum. This construction makes use of a nonlinear realization of the single mode para-Bose (para-Fermi) algebra in terms of a single boson.

Quantum Fluctuation of Mesoscopic Capacitance Coupled Circuit in a Thermal Vacuum State

2003 ◽  
Vol 20 (12) ◽  
pp. 2231-2234
Author(s):  
Zhu Ai-Dong ◽  
Zhang Shou ◽  
Jin Zhe ◽  
Zhao Yong-Fang ◽  
Jing Xiao-Gong ◽  
...  
Keyword(s):  
Quantum Fluctuation ◽  
Vacuum State ◽  
Thermal Vacuum ◽  
Thermal Vacuum State

THE QUANTUM FLUCTUATIONS OF MESOSCOPIC DAMPED MUTUAL INDUCTANCE COUPLED DOUBLE RESONANCE RLC CIRCUIT AT FINITE TEMPERATURE

2007 ◽  
Vol 21 (27) ◽  
pp. 4725-4738 ◽  
Author(s):  
XING-LEI XU ◽  
HONG-QI LI ◽  
SHI-MIN XU ◽  
JI-SUO WANG
Keyword(s):  
Environmental Temperature ◽  
Energy Levels ◽  
Double Resonance ◽  
Quantum Fluctuations ◽  
Vacuum State ◽  
Mutual Inductance ◽  
Squeezed State ◽  
Thermal Vacuum ◽  
Thermo Field Dynamics ◽  
Rlc Circuit

Mesoscopic damped mutual inductance coupled double resonance RLC circuit is quantized by the method of damped harmonic oscillator quantization and linear transformation. The energy levels of this circuit are given. By thermo-field dynamics (TFD), the quantum fluctuations of the current and voltage of each loop are researched in the thermal vacuum state, thermal coherent state and thermal squeezed state. It is shown that the quantum fluctuations of the current and voltage are related not only to the circuit inherent parameter and coupled magnitude of mutual inductance, but also squeezed coefficients, squeezed angle, environmental temperature and damped resistance. Furthermore, because of environmental temperature and damped resistance, the quantum fluctuations increase with the increase of temperature and decay along with time.

Thermal vacuum state corresponding to squeezed chaotic light and its application

2015 ◽  
Vol 24 (12) ◽  
pp. 120301 ◽  
Author(s):  
Zhi-Long Wan ◽  
Hong-Yi Fan ◽  
Zhen Wang
Keyword(s):  
Vacuum State ◽  
Thermal Vacuum ◽  
Thermal Vacuum State
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