Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Acta Physica Sinica

Study on the influence of quantum state for phonon bath on the quantum behavior of mesoscopic circuit

Juju Hu, Shihua Cai, Wang Jian-Qiu, Yinghua Ji, 江西师范大学物理系，南昌 330022

Published Jan 1, 2008• 0 citations
Publisher

Abstract

Taking into account the interaction between electrons and phonons, we study the dynamical behavior of a mesoscopic dissipative circuit for two classes of pure initial states (grand canonical ensemble and number state) of phonon bath modes. In the long time limit t→∞: when the environment is initially at thermal equilibrium, the average values of current and charge in the circuit system will only depend on the average values of the circuit in initial quantum state, and they are not related with the environment; when the environment is initially in number state, the time evolution of the average values of current and charge are just the same as that in thermal equilibrium, which indicates that the average values of current and charge are related to certain set of occupied numbers. The quantum fluctuations of current and charge in the circuit not only depend on the initial state of the system but also depend on the quantum state and temperature of the environment. Generally, the entanglement between the circuit system and environment will lead to the reduction of the purity of the quantum state. The mesoscopic circuit will remain in a pure quantum state only when the environment is at very low temperature and at thermal equilibrium.

DOI
10.7498/aps.57.496

Related papers

Study on Quantum Entanglement Between Mesoscopic Circuit and Environment at Coherent State

Yinghua Ji

Taking into account the interaction between electrons and phonons, in the case without-rotating-wave approximation, we study the entangling property between the mesoscopic circuit and environment at coherent state or equilibrium state. The result indicates that, in long time limit t → ∞, the averages of charge and current in the circuit only depend on the average of the system at the initial state when the environment is initially at thermal equilibrium. However, when the environment is initially at coherent state, the average of charge and current in the circuit is determined by the specific coherent state ensemble. Generally speaking, the entanglement between the circuit and environment will lead to the quantum state purity declining of the circuit, then the circuit emerges decoherent phenomenon, and so a mixed state appears. Purity changes are related to the initial quantum state of environment and circuit. With the further evolution of time, coherence will be gradually restored, but cannot return to 1.

Communications in Theoretical Physics•Oct 1, 2008•2 citations

Time dependence of the average charge and current in a dissipative mesoscopic circuit

Yinghua Ji, Lei Min-Sheng, Ouyang Chu-Ying

Taking into consideration the interactions between electrons and phonons, we have studied the temporal evolution of the average charge and current in a dissipative mesoscopic RLC circuit. Our results show that a mesoscopic RLC circuit can be treated as an interactive system between an electromagnetic harmonic oscillator and many lattice harmonic oscillators; this is called the bathing of the harmonic oscillators. The results also show that the quantum equation of motion of the linear mesoscopic RLC circuit is identical in form to its classical equation of motion, the only difference between them being their respective meanings. In order to thoroughly study the quantum properties of a dissipative mesoscopic circuit, we have to consider not only the electromagnetic energy of the circuit, but also the crystal lattice vibration energy and the interactive energy between electrons and phonons.

Chinese Physics•Jan 22, 2002•12 citations

Time dependence of the average charge and current in a dissipative mesoscopic circuit

嵇英华, 雷敏生, 欧阳楚英

Taking into consideration the interactions between electrons and phonons,we have studied the temporal evolution of the average charge and current in a dissipative mesoscopic RLC circuit.Our results show that a mesoscopic RLC circuit can be treated as an interactive system between an electromagnetic harmonic oscillator and many lattice harmonic oscillators;this is called the bathing of the harmonic oscillators.The results also show that the quantum equation of motion of the linear mesoscopic RLC circuit is identical in form to its classical equation of motion,the only difference between them being their respective meanings.In order to thoroughly study the quantum properties of a dissipative mesoscopic circuit,we have to consider not only the electromagnetic energy of the circuit,but also the crystal lattice vibration energy and the interactive energy between electrons and phonons.

中国物理B：英文版•Jun 13, 2005•0 citations

The Dissipative Properties of Josephson Charge Qubit

Ji Ying

Beginning with two different initial states for the bath modes(equilibrium states and number states),time evolution of Josephson charge quantum bit linearly coupled to a heat bath is investigated thoroughly.The couclusion shows: if the bath modes are initially in number states,then decay time of turnable operator is longer and asymptotical value of population operator is smaller than that if the equilibrium states are at high temperature.The dynamic properties of the charge quantum bit are not related to initial states if the bath mode are at low temperature.

Acta Sinica Quantum Optica•Jan 1, 2008•0 citations

Quantum fluctuations of dissipative mesoscopic RLC series and parallel circuit in thermal vacuum state

Kong Ling-ji

By using canonical quantization method of damped harmonic oscillator,the quantum of dissipative mesoscopic RLC series and parallel circuit was realized in this paper.And on this basis,the quantum fluctuations of charge and inductance flux linkage as the same as voltage and current in circuit under thermal vacuum state which based on thermal field dynamics theory were also studied through this research methods.The results show that charge and inductance flux linkage as the same as voltage and current in circuit under thermal vacuum state respectively exist quantum fluctuations.And the quantum fluctuations and quantum fluctuations plot not only depend on device parameters in the circuit,but also depend on time and temperature.

Journal of Northeast Normal University•Jan 1, 2015•0 citations

The Quantum Fluctuations in the Dissipative Mesoscopic Circuit with the Charge Discreteness under Fock State

Hailan Jin, Cui Yuan-shun

On the basis of the charge quantization,the quantum fluctuations of the charge,the current and the energy in the dissipative mesoscopic circuit are calculated by the character of the minimum shift operator.The results show that,taking account of the charge discreteness,the quantum fluctuation of charge is zero under Fock state,but the fluctuations of the current and the energy aren't zero,which relate with charge quantization,Plank constant and the parameters of the circuits.

Journal of Huaiyin Teachers College•Jan 1, 2007•0 citations
Taking into account the interaction between electrons and phonons, we study the dynamical behavior of a mesoscopic dissipative circuit for two classes of pure initial states (grand canonical ensemble and number state) of phonon bath modes. In the long time limit t→∞: when the environment is initially at thermal equilibrium, the average values of current and charge in the circuit system will only depend on the average values of the circuit in initial quantum state, and they are not related with the environment; when the environment is initially in number state, the time evolution of the average values of current and charge are just the same as that in thermal equilibrium, which indicates that the average values of current and charge are related to certain set of occupied numbers. The quantum fluctuations of current and charge in the circuit not only depend on the initial state of the system but also depend on the quantum state and temperature of the environment. Generally, the entanglement between the circuit system and environment will lead to the reduction of the purity of the quantum state. The mesoscopic circuit will remain in a pure quantum state only when the environment is at very low temperature and at thermal equilibrium.
Taking into account the interaction between electrons and phonons, in the case without-rotating-wave approximation, we study the entangling property between the mesoscopic circuit and environment at coherent state or equilibrium state. The result indicates that, in long time limit t → ∞, the averages of charge and current in the circuit only depend on the average of the system at the initial state when the environment is initially at thermal equilibrium. However, when the environment is initially at coherent state, the average of charge and current in the circuit is determined by the specific coherent state ensemble. Generally speaking, the entanglement between the circuit and environment will lead to the quantum state purity declining of the circuit, then the circuit emerges decoherent phenomenon, and so a mixed state appears. Purity changes are related to the initial quantum state of environment and circuit. With the further evolution of time, coherence will be gradually restored, but cannot return to 1.
Taking into consideration the interactions between electrons and phonons, we have studied the temporal evolution of the average charge and current in a dissipative mesoscopic RLC circuit. Our results show that a mesoscopic RLC circuit can be treated as an interactive system between an electromagnetic harmonic oscillator and many lattice harmonic oscillators; this is called the bathing of the harmonic oscillators. The results also show that the quantum equation of motion of the linear mesoscopic RLC circuit is identical in form to its classical equation of motion, the only difference between them being their respective meanings. In order to thoroughly study the quantum properties of a dissipative mesoscopic circuit, we have to consider not only the electromagnetic energy of the circuit, but also the crystal lattice vibration energy and the interactive energy between electrons and phonons.
Taking into consideration the interactions between electrons and phonons,we have studied the temporal evolution of the average charge and current in a dissipative mesoscopic RLC circuit.Our results show that a mesoscopic RLC circuit can be treated as an interactive system between an electromagnetic harmonic oscillator and many lattice harmonic oscillators;this is called the bathing of the harmonic oscillators.The results also show that the quantum equation of motion of the linear mesoscopic RLC circuit is identical in form to its classical equation of motion,the only difference between them being their respective meanings.In order to thoroughly study the quantum properties of a dissipative mesoscopic circuit,we have to consider not only the electromagnetic energy of the circuit,but also the crystal lattice vibration energy and the interactive energy between electrons and phonons.
Beginning with two different initial states for the bath modes(equilibrium states and number states),time evolution of Josephson charge quantum bit linearly coupled to a heat bath is investigated thoroughly.The couclusion shows: if the bath modes are initially in number states,then decay time of turnable operator is longer and asymptotical value of population operator is smaller than that if the equilibrium states are at high temperature.The dynamic properties of the charge quantum bit are not related to initial states if the bath mode are at low temperature.
By using canonical quantization method of damped harmonic oscillator,the quantum of dissipative mesoscopic RLC series and parallel circuit was realized in this paper.And on this basis,the quantum fluctuations of charge and inductance flux linkage as the same as voltage and current in circuit under thermal vacuum state which based on thermal field dynamics theory were also studied through this research methods.The results show that charge and inductance flux linkage as the same as voltage and current in circuit under thermal vacuum state respectively exist quantum fluctuations.And the quantum fluctuations and quantum fluctuations plot not only depend on device parameters in the circuit,but also depend on time and temperature.