Decohering power of thermal fluctuating electromagnetic field with a boundary

2019 ◽  
Vol 34 (26) ◽  
pp. 1950177
Author(s):  
Zhiming Huang ◽  
Wei Zhang ◽  
Shenggen Zheng ◽  
Tianqing Wang ◽  
Yungang Bian ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Master Equation ◽  
Quantum Coherence ◽  
Boundary Effect ◽  
Plane Boundary ◽  
Thermal Bath ◽  
Atomic Position ◽  
Vacuum Fluctuation ◽  
System Evolution ◽  
Field Temperature

In this paper, we analyze the decohering power behaviors for an atom immersed in a thermal bath of fluctuating electromagnetic field in the presence of a perfectly reflecting plane boundary. Firstly, we analytically solve the master equation that governs the system evolution. Then, we discuss the behaviors of decohering power for an atom affected by thermal fluctuating electromagnetic field. It is found that the behaviors of decohering power are dependent on the field temperature, atomic position and polarization. Decohering power fluctuates to relatively stable values with the increasing atom’s distance from the boundary, which suggests a possible way of detecting the vacuum fluctuating and boundary effect. Additional conditions on the electromagnetic field give one more freedom to manipulate the variations of decohering power. Decohering power variations can efficiently reflect the behaviors of quantum coherence affected by electromagnetic vacuum fluctuation, and it is shown that quantum coherence can be effectively enhanced with the presence of a reflecting boundary.

Quantum-memory-assisted entropic uncertainty in fluctuating electromagnetic field with a boundary

2019 ◽  
Vol 34 (17) ◽  
pp. 1950099
Author(s):  
Zhiming Huang ◽  
Xiaobin Wang ◽  
Yiyong Ye ◽  
Xiaokui Sheng ◽  
Zhenbang Rong ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Master Equation ◽  
Quantum Correlation ◽  
Uncertainty Relation ◽  
Boundary Effect ◽  
Quantum Memory ◽  
Plane Boundary ◽  
Evolution Time ◽  
Entropic Uncertainty Relation ◽  
Level Atom

In this work, we investigate the dynamics of quantum-memory-assisted entropic uncertainty relation for a two-level atom coupled with fluctuating electromagnetic field in the presence of a perfectly reflecting plane boundary. The solution of the master equation that governs the system evolution is derived. We find that entropic uncertainty and mixedness increase to a stable value with evolution time, but quantum correlation reduces to zero with evolution time. That is, the mixedness is positively associated with entropic uncertainty, however, increasing quantum correlation can cause the decrease of the uncertainty. The tightness of entropic uncertainty grows at first and then declines to zero with evolution time. In addition, entropic uncertainty fluctuates to relatively stable values with increasing the atom’s distance from the boundary, especially for short evolution time, which suggests a possible way of testing the vacuum fluctuating and boundary effect. Finally, we propose an effective method to control the uncertainty via quantum weak measurement reversal.

Dynamics of quantum correlation for circularly accelerated atoms immersed in a massless scalar field near a boundary

2019 ◽  
Vol 34 (36) ◽  
pp. 1950297
Author(s):  
Zhiming Huang ◽  
Yiyong Ye ◽  
Xiaobin Wang ◽  
Xiaokui Sheng ◽  
Xiaoyun Xia ◽  
...  
Keyword(s):  
Scalar Field ◽  
Master Equation ◽  
Quantum Correlation ◽  
Plane Boundary ◽  
Thermal Bath ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
System Evolution

In this paper, we explore the dynamics of quantum correlation for two circularly accelerated atoms interacting with a bath of fluctuating massless scalar field with a reflecting plane boundary. First, we derive the master equation that governs the system evolution. Then we analyze the behaviors of quantum correlation for various conditions and compare the behaviors of quantum correlation with that of the static atoms immersed in a thermal bath with a boundary. It is found that the dynamics of quantum correlation for circularly accelerated atoms present some features distinct from those of static atoms immersed in a thermal bath.

scholarly journals Open quantum entanglement: a study of two atomic system in static patch of de Sitter space

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Samim Akhtar ◽  
Sayantan Choudhury ◽  
Satyaki Chowdhury ◽  
Debopam Goswami ◽  
Sudhakar Panda ◽  
...  
Keyword(s):  
Scalar Field ◽  
Density Matrix ◽  
Master Equation ◽  
Quantum Entanglement ◽  
De Sitter Space ◽  
Thermal Bath ◽  
Massless Scalar Field ◽  
De Sitter ◽  
Open Quantum ◽  
Non Locality

Abstract In this work, our prime objective is to study non-locality and long range effect of two body correlation using quantum entanglement from various information theoretic measure in the static patch of de Sitter space using a two body Open Quantum System (OQS). The OQS is described by a system of two entangled atoms, surrounded by a thermal bath, which is modelled by a massless probe scalar field. Firstly, we partially trace over the bath field and construct the Gorini Kossakowski Sudarshan Lindblad (GSKL) master equation, which describes the time evolution of the reduced subsystem density matrix. This GSKL master equation is characterized by two components, these are-Spin chain interaction Hamiltonian and the Lindbladian. To fix the form of both of them, we compute the Wightman functions for probe massless scalar field. Using this result alongwith the large time equilibrium behaviour we obtain the analytical solution for reduced density matrix. Further using this solution we evaluate various entanglement measures, namely Von-Neumann entropy, R$$e'$$e′nyi entropy, logarithmic negativity, entanglement of formation, concurrence and quantum discord for the two atomic subsystem on the static patch of De-Sitter space. Finally, we have studied violation of Bell-CHSH inequality, which is the key ingredient to study non-locality in primordial cosmology.

SYMMETRY PROPERTIES IN THE STUDY OF THE RAYLEIGH-TYPE OPTICAL MIXING SIGNAL IN PRESENCE OF A THERMAL BATH

2013 ◽  
Vol 22 (01) ◽  
pp. 1350007
Author(s):  
J. L. PAZ ◽  
A. MASTRODOMENICO ◽  
M. A. IZQUIERDO
Keyword(s):  
Electromagnetic Field ◽  
Molecular System ◽  
Thermal Bath ◽  
Bloch Equations ◽  
System A ◽  
Symmetry Properties ◽  
Intensity Response ◽  
Optical Mixing ◽  
Cumulant Expansions

In this work are studied the symmetry properties of the Rayleigh-type optical mixing signal of a two-level molecular system immersed in a thermal bath and irradiated by a classical electromagnetic field. The solvent induces a random shift of the Bohr frequency in the molecular system. A methodology based in cumulant expansions is employed to obtain the average of the coherences, populations, and susceptibilities of Fourier components associated, calculated by the optical stochastic Bloch equations. These symmetry properties show the dependence of the measured spectra with the variations in the frequencies of the incident fields. Our results show that the inclusion of the thermal bath diminishes the intensity response as well it promotes the loss of the symmetry properties, compared with the same results in the absence of the bath.

Steady-state correlations of two atoms interacting with a reservoir

2012 ◽  
Vol 12 (3&4) ◽  
pp. 231-252
Author(s):  
Luis Octavio Castanos
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Master Equation ◽  
Field Intensity ◽  
Mixed State ◽  
Laser Field ◽  
Quantum Discord ◽  
Energy Levels ◽  
High Laser ◽  
X State

We consider two two-level atoms fixed at different positions, driven by a resonant monochromatic laser field, and interacting collectively with the quantum electromagnetic field. A Born-Markov-secular master equation is used to describe the dynamics of the two atoms and the steady-state is obtained analytically for a configuration of the atoms. The steady-state populations of the energy levels of the free atoms, entanglement, quantum and geometric discords and degree of mixedness are calculated analytically as a function of the laser field intensity and the distance between the two atoms. It is found that there is a possibility of considerable steady-state entanglement and left/right quantum discord and that these can be controlled either by increasing/decreasing the intensity of the laser field or by increasing/decreasing the distance between atoms. It is shown that the system of two atoms can be prepared in a separable mixed state with non-zero quantum discord that turns into an $X$-state for high laser field intensities. The behavior and relationships between the different correlations are studied and several limiting cases are investigated.

scholarly journals Velocity effect on the stimulated transition process of a multilevel atom in a thermal bath

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Huabing Cai
Keyword(s):  
Electromagnetic Field ◽  
Perturbation Theory ◽  
Transition Process ◽  
Stimulated Emission ◽  
Atomic Transition ◽  
Thermal Bath ◽  
Transition Rates ◽  
Atomic Polarizability ◽  
Velocity Effect ◽  
Multilevel Atom

AbstractThis paper investigates the stimulated transition process of a uniformly moving atom in interaction with a thermal bath of the quantum electromagnetic field. Using the perturbation theory, the atomic stimulated emission and absorption rates are calculated. The results indicate that the atomic transition rates depend crucially on the atomic velocity, the temperature of the thermal bath, and the atomic polarizability. As these factors change, the atomic stimulated transition processes can be enhanced or weakened at different degrees. In particular, slowly moving atoms in the thermal bath with high temperature ($$T\gg \omega _{0}$$ T ≫ ω 0 ) perceive a smaller effective temperature $$T \big ( 1-\frac{1}{10} v^{2} \big )$$ T ( 1 - 1 10 v 2 ) for the polarizability perpendicular to the atomic velocity or $$T \big ( 1-\frac{3}{10} v^{2} \big )$$ T ( 1 - 3 10 v 2 ) for the polarizability parallel to the atomic velocity. However, ultra-relativistic atoms perceive no influence of the background thermal bath. In turn, in terms of the atomic transition rates, this paper explores and examines the relativity of temperature of the quantum electromagnetic field.

Teleportation affected by fluctuating electromagnetic field with a boundary

2021 ◽  
Author(s):  
Zhiming Huang ◽  
Zhenbang Rong ◽  
Yiyong Ye
Keyword(s):  
Electromagnetic Field ◽  
Quantum Information ◽  
Quantum System ◽  
Quantum Teleportation ◽  
Quantum Communication ◽  
Open Quantum System ◽  
Plane Boundary ◽  
Atomic Polarization ◽  
Electromagnetic Fluctuation ◽  
Insight Into

We study the quantum teleportation under fluctuating electromagnetic field in the presence of a perfectly reflecting boundary. The noisy scheme of quantum teleportation affected by electromagnetic fluctuation is proposed. Then we calculate and investigate the behaviors of entanglement and fidelity, which are closely related to the plane boundary and atomic polarization. After a period of evolution, entanglement and fidelity evolve to zero and nonzero stable value respectively. Fidelity is closely related to the weight parameter and phase parameter of the teleported state. Besides, small two-atom separation makes entanglement and fidelity have better enhancement. Furthermore, the presence of boundary, atomic polarization and two-atom separation offers us more freedom to adjust the performance of the quantum teleportation. The results would give us new insight into quantum communication in an open quantum system since quantum teleportation plays an important role in quantum communication and quantum information.

scholarly journals Research on the Electromagnetic-Heat-Flow Coupled Modeling and Analysis for In-Wheel Motor

2020 ◽  
Vol 11 (2) ◽  
pp. 29
Author(s):  
Haojie Xue ◽  
Di Tan ◽  
Shuaishuai Liu ◽  
Meng Yuan ◽  
Chunming Zhao
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Flow Field ◽  
Weak Coupling ◽  
Working Condition ◽  
Electromagnetic Torque ◽  
Coupling Analysis ◽  
Field Coupling ◽  
Field Temperature ◽  
Coupling Factors

In this paper, a 15 KW in-wheel motor (IWM) is taken as the research object, and the coupling factors among the electromagnetic field, temperature field and flow field are analyzed, and the strong and weak coupling factors between the three fields are clarified, and by identifying the strong and weak coupling factors between the three fields, a three-field coupling analysis model for IWM with appropriate complexity is established, and the validity of the model is verified. In a certain driving condition, the electromagnetic field, temperature field and flow field characteristics of IWM are analyzed with the multi-field coupling model. The result shows that, after the IWM runs 8440 s under driving conditions, in this paper, the IWM electromagnetic torque of the rated working condition is 134.2 Nm, and IWM the electromagnetic torque of the peak working condition is 451.36 Nm, and the power requirement of the motor can be guaranteed. The highest temperature of the IWM is 150 °C, which does not exceed the insulation grade requirements of the motor (155 °C), the highest temperature of the permanent magnet (PM) is 65.6 °C, and it does not exceed the highest operating temperature of the PM, and ensures the accurate calculation of components loss and the temperature of the motor. It can be found, through research, that the electromagnetic torque difference between unidirectional coupling and bidirectional coupling is 3.2%, the maximum temperature difference is 7.98% in the three-field coupling analysis of IWM under rated working conditions. Therefore, it is necessary to consider the influence of coupling factors on the properties of motor materials when analyzing the electromagnetic field, temperature field and flow field of IWM; it also provides some reference value for the simulation analysis of IWM in the future.

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