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Communications in Theoretical Physics 2024年第8期76卷 60-66页

作者： Maryam Hadipour Soroush Haseli Saeed Haddadi Faculty of Physics Urmia University of TechnologyUrmiaIran School of Physics Institute for Research in Fundamental Sciences(IPM)PO Box 19395-5531TehranIran Faculty of Physics Semnan UniversityPO Box 35195-363SemnanIran

Following the recent paper(Teittinen et al 2019 New J. Phys. 21 123041), one can see that in general there is no simple relation between non-markovianity and quantum speed limit. Here, we investigate the connection between quantum speed limit time and non-markovianity of an atom in structured environments(reservoirs) whose dynamics is governed by an exact pseudomode master equation(Garraway 1997 Phys. Rev. A 55 2290). In particular, we find an inverse relation between them, which means that the non-Markovian feature of the quantum process leads to speedup of evolution. Thus, there is a link between quantum speedup and memory effects for specific cases of dynamical evolution. Our results might shed light on the relationship between the speedup of quantum evolution and the backflow of information from the environment to the system.

关键词： quantum speed limit non-markovianity pseudomode method structured environments

non-markovianity of an atom in a semi-infinite rectangular waveguide

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Chinese Physics B 2023年第3期32卷 102-110页

作者：曾静宋亚菊卢竞周兰 Key Laboratory of Low-Dimensional Quantum Structures and and Quantum Control of the Ministry of Education Department of Physics and Synergetic Innovation Center of Quantum Effects and ApplicationsKey Laboratory for Matter Microstructure and Function of Hunan ProvinceHunan Normal UniversityChangsha 410081China College of Physics and Electronic Engineering Hengyang Normal UniversityHengyang 421002China

We investigate the non-markovianity(NM)of a waveguide QED with a two-level atom as the system and a semiinfinite rectangular waveguide as the environment,where the transverse magnetic(TM_(mn))modes define the quantum channels of guided *** perfect mirror imposed by the finite end exerts a retarded feedback mechanism to allow for information backflow,which leads to NM *** the energy separation of the atom far away from the cutoff frequencies of transverse modes,the delay differential equations are obtained with single-excitation initial in the *** attention is focused on the effects of multiple quantum channels involved in guiding photons on the degree of nonMarkovian *** asymptotic value of the non-markovianity N_(1)can be found as the atom–mirror distance is large enough,however,the asymptotic value of N_(2)of the atom interacting with the effective double-modes is lower than that of the atom interacting with the effective *** also show that N_(1)is a constant,and the analytical expression for N_(2)is related to the parameters associated with the modes,which is related to the interference of the two modes.

关键词： open system non-markovianity waveguide QED quantum information

non-markovianity of a qubit coupled with an isotropic Lipkin–Meshkov–Glick bath

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Chinese Physics B 2015年第10期24卷 59-66页

作者：田立君提敏敏翟向东 Department of Physics Shanghai University

We study the non-markovianity of the single qubit system coupled with an isotropic Lipkin-Meshkov-Glick（LMG）model by an effective method proposed by Breuer et al.（Breuer H P and Piilo J 2009 Europhys. Lett. 85 5004）. It is discovered that the non-markovianity is concerned with the quantum phase transitions（QPTs）. In the open system, we present that the strong coupling inside the bath and the strong interaction between the system and bath can enhance the degree of non-markovianity. Moreover, the non-markovianity is stronger and more sensitive for the bath in the symmetric phase than the symmetry broken phase.

关键词： non-markovianity qubit dynamics LMG model

non-markovianity and Indivisible Quantum dynamics of a Apin-S System

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Communications in Theoretical Physics 2013年第9期60卷 308-312页

作者：郝翔许雪芬朱士群 Department of Physics Renmin University of China School of Mathematics and Physics Suzhou University of Science and Technology School of Physical Science and Technology Soochow University

Using a measure for the divisibility of a dynamical map, we study the non-Markovian character of a quantum evolution of a spin-S system, which is in an external field and weakly coupled to a bosonic bath with a certain temperature. The finite-temperature dynamics of the open system is obtained by the time-convolutionless master equation in the secular approximation. Besides the influence of the environmental spectral density function, the external field and low temperatures can affect the quantum non-markovianity. It is found out that the non-Markovian feature of a dynamical map of a high-dimensional spin system is noticeable in contrast to that of a low-dimension spin system.

关键词： non-markovianity indivisibility quantum decoherenc

Dipole–dipole interactions enhance non-markovianity and protect information against dissipation

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Chinese Physics B 2019年第9期28卷 100-106页

作者： Xiao-Ye Xu Qin-Qin Wang Zhe Chen Yong-Jian Han Chuan-Feng Li Guang-Can Guo Key Laboratory of Quantum Information of Chinese Academy of Sciences (CAS) University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

Preserving non-markovianity and quantum entanglement from decoherence effect is of theoretical and practical significance in the quantum information processing *** this context, we study a system S that is initially correlated with an ancilla A, which interacts with the environment E via an amplitude damping *** also consider dipole-dipole interactions(DDIs) between the system and ancilla, which are responsible for strong *** investigate the impact of DDIs and detuning on the non-markovianity and information exchange in different *** show that DDIs are not only better than detuning at protecting the information(without destroying the memory effect) but also induce memory by causing a transition from Markovian to non-Markovian *** contrast, although detuning also protects the information, it causes a transition from non-Markovian to the Markovian *** addition, we demonstrate that the non-markovianity grows with increasing DDI strength and diminishes with increasing *** also show that the effects of negative detuning and DDIs can cancel out each other, causing a certain loss of coherence and information.

关键词： decoherence non-markovianity dipole-dipole interactions entanglement

Entanglement and non-markovianity of a multi-level atom decaying in a cavity

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Chinese Physics B 2016年第1期25卷 440-445页

作者：范子龙任玉坤曾浩生 Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics Hunan Normal University

We present a paradigmatic method for exactly studying non-Markovian dynamics of a multi-level V-type atom interacting with a zero-temperature bosonic bath. Special attention is paid to the entanglement evolution and the dynamical nonmarkovianity of a three-level V-type atom. We find that the entanglement negativity decays faster and non-markovianity is smaller in the resonance regions than those in the non-resonance regions. More importantly, the quantum interference between the dynamical non-Markovianities induced by different transition channels is manifested, and the frequency domains for constructive and destructive interferences are found.

关键词： entanglement negativity non-markovianity quantum interference

Effect of non-markovianity on synchronization

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Communications in Theoretical Physics 2021年第10期73卷 81-89页

作者： Kun-Jie Zhou Jian Zou Bao-Ming Xu Lei Li Bin Shao School of Physics Beijing Institute of TechnologyBeijing 100081China Shandong Key Laboratory of Biophysics Institute of BiophysicsDezhou UniversityDezhou 253023China School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China

We investigate the transient spontaneous quantum synchronization between two qubits interacting with a common non-Markovian environment based on a collision *** are mainly interested in the effect of non-markovianity on the synchronization between two *** find that the non-markovianity always delay the anti-synchronization and decrease the parameter region where the qubits get ***,we define V to characterize the visibility of synchronization and show that there is an apparent link among V,entanglement and quantum mutual information whether in the Markovian or non-Markovian regimes when the environment is in the vacuum ***,with the increase of temperature,the parameter region of the emergence of anti-synchronization and the time to get anti-synchronized in the non-Markovian regime gradually approaches that in the Markovian *** high temperature decreases the parameter region of the emergence of anti-synchronization in both Markovian and non-Markovian regimes,and breaks the connection among V,entanglement and quantum mutual information.

关键词： quantum synchronization non-markovianity entanglement quantum mutual information

Effect of entanglement embedded in environment on quantum non-markovianity based on collision model

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Communications in Theoretical Physics 2021年第5期73卷 46-53页

作者： Xiao-Ming Li Yong-Xu Chen Yun-Jie Xia Zhong-Xiao Man School of Physics and Physical Engineering Shandong Provincial Key Laboratory of Laser Polarization and Information TechnologyQufu Normal UniversityQufu273165China

By means of collision models(CMs)where the environment is simulated by a collection of ancillas consisting of two entangled qubits,we investigate the effects of entanglement in the environment on the non-markovianity of an open quantum *** CMs are considered in this study,in the first one the open quantum system S directly collides with the environment,while in the second one the system interacts with two intermediate qubits which,in turn,are coupled to the *** show that it is possible to enhance the non-markovianity by environment entanglement in both *** particular,in the second model,we show that the initial state of the auxiliary qubits can also affect the non-markovianity of the system and there exists the optimal combination of the initial environmental state and the initial state of auxiliary *** this case,the non-markovianity can be greatly enhanced.

关键词： collision model entanglement non-markovianity

Negativity of Quantumness and non-markovianity in a Qubit Coupled to a Thermal Ising Spin Bath System

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Communications in Theoretical Physics 2014年第11期61卷 634-640页

作者：胡征达张逸新张业奇 School of Science Jiangnan University Department of Mathematics and Physics North China Electric Power University

We propose a scheme to characterize the non-Markovian dynamics and quantify the non-markovianity via the non-classicality measured by the negativity of quantumness. By considering a qubit in contact with a critical Ising spin bath and introducing an ancilla, we show that revivals of negativity of quantumness indicate the non-Markovian ***, a normalized measure of non-markovianity based on the negativity of quantumness is introduced and the influences of bath criticality, bath temperature and bath size on the non-markovianity are discussed. It is shown that,at the critical point, the decay of non-markovianity versus the size of spin bath is the fastest and the non-markovianity is exactly zero only in the thermodynamic limit. Besides, non-trivial behaviours of negativity of quantumness such as sudden change, double sudden changes and keeping constant are found for different relations between parameters of the initial state. Finally, how the non-classicality of the system is affected by a series of bang-bang pulses is also examined.

关键词： non-markovianity negativity of quantumness critical spin bath

non-Markovian speedup dynamics control of the damped Jaynes-Cummings model with detuning

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Chinese Physics B 2018年第1期27卷 247-252页

作者：徐凯韩伟张英杰范桁 Shandong Provincial Key Laboratory of Laser Polarization and Information Technology Department of Physics Qufu Normal University Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Collaborative Innovation Center of Quantum Matter

For a two-level atom in a lossy cavity, a scheme to manipulate the non-Markovian speedup dynamics has been pro- posed in the controllable environment （the lossy cavity field）. We mainly focus on the effects of the qubit--cavity detuning A and the qubit-cavity coupling strength k on the non-Markovian speedup evolution of an open system. By controlling the environment, i.e., tuning zl and , two dynamical crossovers from Markovian to non-Markovian and from no-speedup to speedup are achieved. Furthermore, it is clearly found that increasing the coupling strength k or detuning A in some cases can make the environmental non-markovianity stronger and hence can lead to faster evolution of the open system.

关键词： non-markovianity quantum speed limits open system dynamics