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Entropy variances of pure coherent states in the diffusion channel
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作者 Wei-Feng Wu Yong Fang Peng Fu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期384-388,共5页
Using the operator correspondence of the real and fictious modes in the thermo entangled state representation, wesolve the quantum master equation describing the diffusion channel and obtain the Kraus operator-sum rep... Using the operator correspondence of the real and fictious modes in the thermo entangled state representation, wesolve the quantum master equation describing the diffusion channel and obtain the Kraus operator-sum representation ofits analytical solution. we find that the pure coherent states evolve into the new mixed thermal superposed states in thediffusion channel. Also, we investigate the statistical properties of the initial coherent states and their entropy evolutions inthe diffusion channel, and find that the entropy evolutions are only related to the decay time and without the amplitudes ofthe initial coherent states. 展开更多
关键词 entangled state representation diffusion channel coherent state entropy evolution
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Barut-Girardello and Gilmore-Perelomov coherent states for pseudoharmonic oscillators and their nonclassical properties: Factorization method
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作者 M K Tavassoly H R Jalali 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第8期421-428,共8页
In this paper we try to introduce the ladder operators associated with the pseudoharmonic oscillator, after solving the corresponding Schrrdinger equation by using the factorization method. The obtained generalized ra... In this paper we try to introduce the ladder operators associated with the pseudoharmonic oscillator, after solving the corresponding Schrrdinger equation by using the factorization method. The obtained generalized raising and lowering operators naturally lead us to the Dirac representation space of the system which is much easier to work with, in comparison to the functional Hilbert space. The SU(1, 1) dynamical symmetry group associated with the considered system is exactly established through investigating the fact that the deduced operators satisfy appropriate commutation relations. This result enables us to construct two important and distinct classes of Barut-Girardello and Gilmore-Perelomov coherent states associated with the system. Finally, their identities as the most important task are exactly resolved and some of their nonclassical properties are illustrated, numerically. 展开更多
关键词 pseudoharmonic oscillator factorization method Barut-Girardello coherent states Gilmore-Perelomov coherent states nonclassical properties
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Hong–Ou–Mandel interference with two independent weak coherent states 被引量:4
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作者 陈华 安雪碧 +4 位作者 伍娟 银振强 王双 陈巍 韩正甫 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期76-81,共6页
Recently, the Hong-Ou-Mandel (HOM) interference between two independent weak coherent pulses (WCPs) has been paid much attention due to the measurement-device-independent (MDI) quantum key distribution (QKD). ... Recently, the Hong-Ou-Mandel (HOM) interference between two independent weak coherent pulses (WCPs) has been paid much attention due to the measurement-device-independent (MDI) quantum key distribution (QKD). Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is 〈 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection. 展开更多
关键词 Hong-Ou-Mandel interference weak coherent states measurement-device-independent quantumkey distribution
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Generation of Multi-mode Entangled Coherent States for N Trapped Ions in Strong-Excitation Regime 被引量:2
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作者 ZHENGShi-Biao 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3期523-525,共3页
We propose a scheme to generate entangled coherent states for the vibrational modes of N trapped ions.In the scheme the first ion is sequentially excited by two travelling wave laser fields tuned to the ion transition... We propose a scheme to generate entangled coherent states for the vibrational modes of N trapped ions.In the scheme the first ion is sequentially excited by two travelling wave laser fields tuned to the ion transition. The scheme works in the strong-excitation regime, which is of experimental importance in view of decoherence. 展开更多
关键词 entangled coherent states trapped ion strong-excitation regime
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The Wigner function and phase properties of superposition of two coherent states with the vacuum state 被引量:1
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作者 王月媛 王继成 刘树田 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第7期268-275,共8页
This paper discusses some statistical properties of the superposition of two coherent states with a vacuum state, such as sub-Poissonian photon statistics and negativity of the Wigner function. Phase probability distr... This paper discusses some statistical properties of the superposition of two coherent states with a vacuum state, such as sub-Poissonian photon statistics and negativity of the Wigner function. Phase probability distribution and phase variance are calculated. Special cases of the constructed superposition states are presented. The results show that depending on the vacuum state coefficient γ and the coherent state coefficient a, it can generate a variety of nonclassical states. 展开更多
关键词 coherent states vacuum state Wigner distribution function phase properties
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Amplitude-squared squeezing of superposition of coherent states 被引量:1
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作者 Muhammad Ashfaq Ahmad 任珉 +1 位作者 马爱群 刘树田 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第5期1777-1783,共7页
This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseud... This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseudoclassical states. According to the analysis, it is found that the superposition state of two coherent states with their phase differences π/2 and 3π/2, and the superposition state of two pseudoclassical states both do exhibit the amplitude-squared squeezing. Also, some specific states are found to exhibit even stronger squeezing effects when relative phase of the superposition is equal to the average photon number. Amplitude-squared squeezing is dependent on the difference in phase between two coherent states. 展开更多
关键词 nonclassical states superposition of two coherent states amplitude-squared squeezing
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Quantum Properties of Two-Mode Squeezed Even and Odd Coherent States 被引量:1
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作者 ZHANG Jing WU Wei MENG Shao-Ying 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期317-324,共8页
Two new types of quantum states are constructed by applying the operator s(ξ) = exp(ξ* ab - ξa+b+) on the two-mode even and odd coherent states. The mathematical and quantum statistical properties of such st... Two new types of quantum states are constructed by applying the operator s(ξ) = exp(ξ* ab - ξa+b+) on the two-mode even and odd coherent states. The mathematical and quantum statistical properties of such states are investigated. Various nonclassical features of these states, such as squeezing properties, the inter-mode photon bunching, and the violation of Cauchy-Schwarz inequality, are discussed. The Wigner function in these states are studied in detail. 展开更多
关键词 two-mode squeezed even/odd coherent states quantum statistical properties
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Using Coherent States to Make Physically Correct Classical-to-Quantum Procedures That Help Resolve Nonrenomalizable Fields Including Einstein’s Gravity 被引量:6
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作者 John R. Klauder 《Journal of High Energy Physics, Gravitation and Cosmology》 2021年第3期1019-1026,共8页
Canonical quantization covers a broad class of classical systems, but that does not include all the problems of interest. Affine quantization has the benefit of providing a successful quantization of many important pr... Canonical quantization covers a broad class of classical systems, but that does not include all the problems of interest. Affine quantization has the benefit of providing a successful quantization of many important problems including the quantization of half-harmonic oscillators [1], non-renormalizable scalar fields, such as (<i>ϕ</i><sup>12</sup>)<sub>3</sub> [2] and (<i>ϕ</i><sup>12</sup>)<sub>3</sub> [3], as well as the quantum theory of Einstein’s general relativity [4]. The features that distinguish affine quantization are emphasized, especially, that affine quantization differs from canonical quantization only by the choice of classical variables promoted to quantum operators. Coherent states are used to ensure proper quantizations are physically correct. While quantization of non-renormalizable covariant scalars and gravity are difficult, we focus on appropriate ultralocal scalars and gravity that are fully soluble while, in that case, implying that affine quantization is the proper procedure to ensure the validity of affine quantizations for non-renormalizable covariant scalar fields and Einstein’s gravity. 展开更多
关键词 Physical Quantization coherent states Affine Quantization Non-Renormalizable Models Ultralocal Solutions
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Quantum statistical properties of photon-added spin coherent states 被引量:1
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作者 G Honarasa 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第11期206-209,共4页
The photon-added spin coherent state as a new kind of coherent state has been defined by iterated actions of the proper raising operator on the ordinary spin coherent state. In this paper, the quantum statistical prop... The photon-added spin coherent state as a new kind of coherent state has been defined by iterated actions of the proper raising operator on the ordinary spin coherent state. In this paper, the quantum statistical properties of photon-added spin coherent states such as photon number distribution, second-order correlation function and Wigner function are studied. It is found that the Wigner function shows the negativity in some regions and the second-order correlation function is less than unity. Therefore, the photon-added spin coherent state is a nonclassical state. 展开更多
关键词 photon-added spin coherent states photon number distribution Wigner function
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Maximal entanglement from photon-added nonlinear coherent states via unitary beam splitters
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作者 K.Berrada 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第2期295-302,共8页
In this paper, we construct photon-added f-deformed coherent states (PAf-DCSs) for nonlinear bosonic fields by discussing Klauder's minimal set of conditions required to obtain coherent states. Using this set of no... In this paper, we construct photon-added f-deformed coherent states (PAf-DCSs) for nonlinear bosonic fields by discussing Klauder's minimal set of conditions required to obtain coherent states. Using this set of nonlinear states, we propose a very useful scheme for generating the maximal amount of entanglement via unitary beam splitters for different strength regimes of the input field α, deformation q and excitation number m. Therefore, the possibility to create highly entangled states and to control the entanglement is proposed. Moreover, the condition for a maximal and separable output beam state is obtained. Finally, we examine the statistical properties of the PAf-DCSs through the Mandel parameter and exploit a connection between this quantity and the behavior variation of the output state entanglement. Our result may open new perspectives in different tasks of quantum information processing. 展开更多
关键词 photon-added nonlinear coherent states beam splitter linear entropy ENTANGLEMENT statistical properties
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Wave packet dynamics of nonlinear Gazeau–Klauder coherent states of a position-dependent mass system in a Coulomb-like potential
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作者 Faustin Blaise Migueu Mercel Vubangsi +1 位作者 Martin Tchoffo Lukong Cornelius Fai 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第6期154-163,共10页
AD = 1 position-dependent mass approach to constructing nonlinear quantum states for a modified Coulomb potential is used to generate Gazeau–Klauder coherent states. It appears that their energy eigenvalues are scale... AD = 1 position-dependent mass approach to constructing nonlinear quantum states for a modified Coulomb potential is used to generate Gazeau–Klauder coherent states. It appears that their energy eigenvalues are scaled down by the quantum number and the nonlinearity coefficient. We study the basic properties of these states, which are found to be undefined on the whole complex plane, and some details of their revival structure are discussed. 展开更多
关键词 deformed Coulomb potential energy spectrum coherent states photon number distribution quantum revivals
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Generation of Four-Mode Cluster-Type Entangled Coherent States in Free-Traveling Optical Fields
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作者 HE Dai-Guo DONG Yu-Li FANG Jian-Xing QIAN Li HU Jie 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第3期426-430,共5页
In this paper, we propose an optical scheme to generate four-mode cluster-type entangled coherent states (ECSs) in free traveling optical fields by using two single-photon sources, coherent state sources, beam split... In this paper, we propose an optical scheme to generate four-mode cluster-type entangled coherent states (ECSs) in free traveling optical fields by using two single-photon sources, coherent state sources, beam splitters, pho- todetectors, cross-Kerr media, and phase shifters. And the success probability of the states preparation is calculated. At last we discuss the experimental feasibility of such proposal. 展开更多
关键词 cluster states coherent states beam splitters cross-Kerr media
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A New Kind of k-Quantum Nonlinear Coherent States: Their Generation and PhysicalMeaning
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作者 WANGJi-Suo LIUTang-Kun +2 位作者 FENGJian SUNJin-Zuo ZHANMing-Sheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第6期935-940,共6页
A new kind of k-quantum nonlinear coherent states,i.e.,the k eigenstates of the k-th power~k (k≥3) of the generalized annihilation operator=1/f() of f-oscillators,are obtained and their properties are discussed.The c... A new kind of k-quantum nonlinear coherent states,i.e.,the k eigenstates of the k-th power~k (k≥3) of the generalized annihilation operator=1/f() of f-oscillators,are obtained and their properties are discussed.The completeness of the k states is investigated.An alternative method to construct them is proposed.It is shown that these states may form a complete Hilbert space,and all of them can be generated by a linear superposition of k Roy-type nonlinear coherent states.Physically,they can be generated by a linear superposition of the time-dependent Roy-type nonlinear coherent states at different instants. 展开更多
关键词 orthonormalized eigenstate k-quantum nonlinear coherent states COMPLETENESS physical meaning
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Coupling Between the Group—Related Coherent States
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作者 LIGuang-Hua HEHui-Yong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第1期1-6,共6页
When two representations of the Lie algebra are coupled, the coupling integral kernels are presented to relate the coupled to uncoupled group-related coherent states. These kernels have a connection with usual couplin... When two representations of the Lie algebra are coupled, the coupling integral kernels are presented to relate the coupled to uncoupled group-related coherent states. These kernels have a connection with usual coupling coefficients. The explicit expressions of these kernels for and are given. When the direct product of three representations is formed in two ways, the recoupling integral kernels relating to the coupled group-related coherent states corresponding to two different schemes are introduced, and the relations between these kernels and the general recoupling coefficients are obtained. The properties of these kernels are discussed. 展开更多
关键词 group-related coherent states coupling coefficients coupling integral kernel recoupling integral kernel
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Quantum dual signature scheme based on coherent states with entanglement swapping
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作者 刘佳丽 施荣华 +2 位作者 石金晶 吕格莉 郭迎 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第8期44-52,共9页
A novel quantum dual signature scheme, which combines two signed messages expected to be sent to two diverse receivers Bob and Charlie, is designed by applying entanglement swapping with coherent states. The signatory... A novel quantum dual signature scheme, which combines two signed messages expected to be sent to two diverse receivers Bob and Charlie, is designed by applying entanglement swapping with coherent states. The signatory Alice signs two different messages with unitary operations(corresponding to the secret keys) and applies entanglement swapping to generate a quantum dual signature. The dual signature is firstly sent to the verifier Bob who extracts and verifies the signature of one message and transmits the rest of the dual signature to the verifier Charlie who verifies the signature of the other message. The transmission of the dual signature is realized with quantum teleportation of coherent states. The analysis shows that the security of secret keys and the security criteria of the signature protocol can be greatly guaranteed.An extensional multi-party quantum dual signature scheme which considers the case with more than three participants is also proposed in this paper and this scheme can remain secure. The proposed schemes are completely suited for the quantum communication network including multiple participants and can be applied to the e-commerce system which requires a secure payment among the customer, business and bank. 展开更多
关键词 quantum dual signature coherent states entanglement swapping quantum communication network
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Amplitude-squared squeezing of the generalized odd-even coherent states of the anharmonic oscillator in a finite-dimensional Hilbert space
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作者 Muhammad Ashfaq Ahmad 林杰 +3 位作者 钱妍 马志民 马爱群 刘树田 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第5期1351-1356,共6页
This paper discusses the properties of amplitude-squared squeezing of the generalized odd-even coherent states of anharmonic oscillator in finite-dimensional Hilbert space. It demonstrates that the generalized odd coh... This paper discusses the properties of amplitude-squared squeezing of the generalized odd-even coherent states of anharmonic oscillator in finite-dimensional Hilbert space. It demonstrates that the generalized odd coherent states do exhibit strong amplitude-squared squeezing effects in comparison with the generalized even coherent states. 展开更多
关键词 squeezing effect generalized even and odd coherent states anharmonic oscillator finite-dimensional Hilbert space
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Coherent States and a Path Integral for the Relativistic Linear Singular Oscillator
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作者 S.M.Nagiyev E.I.Jafarov M.Y.Efendiyev 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第2期315-318,共4页
The SU(1,1) coherent states for a relativistic model of the linear singular oscillator are considered. The corresponding partition function is evaluated. The path integral for the transition amplitude between SU(1,... The SU(1,1) coherent states for a relativistic model of the linear singular oscillator are considered. The corresponding partition function is evaluated. The path integral for the transition amplitude between SU(1,1) coherent states is given. Classical equations of the motion in the generalized curved phase space are obtained. It is shown that the use of quasiclassical Bohr Sommerfeld quantization rule yields the exact expression for the energy spectrum. 展开更多
关键词 relativistic linear singular oscillator SU(1 1) coherent states path integral
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Study of Concurrence and D-Concurrence on Two-Qubits Resulted in Pair Coherent States in Language of SU(2) Coherent States
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作者 S.Salimi A.Mohammadzade 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第8期241-246,共6页
Pair coherent state, is a state of a two-mode radiation field that is known as a state with non-gaussian wave function. In this paper, study on the pair coherent state, we notice that with superposition of two first t... Pair coherent state, is a state of a two-mode radiation field that is known as a state with non-gaussian wave function. In this paper, study on the pair coherent state, we notice that with superposition of two first terms of this states, one two-qubits formed. Because of the importance of two-qubits in theory of quantum entanglement, with two different measures with the title of concurrence and D-concurrence, we have studied the amount of entanglement and discussed its details. At the end, we describe these measures for pair coherent states as a function of the amplitude of the SU(2) coherent states. 展开更多
关键词 ENTANGLEMENT pair coherent states CONCURRENCE
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Realistic teleportation of coherent states using squeezed vacuum states
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作者 闫伟 张为俊 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第9期2584-2586,共3页
This paper presents a realistic scheme for the teleportation of coherent states in which a two-mode squeezed vacuum state serves as the quantum channel and the position-sum and momentum-difference of two local modes s... This paper presents a realistic scheme for the teleportation of coherent states in which a two-mode squeezed vacuum state serves as the quantum channel and the position-sum and momentum-difference of two local modes serve as the measuring observables. The average fidelity of the teleportation of coherent states is derived for finite squeezing parameters and it turns out that fidelity greater than 1/2 cannot be achieved by using a classical channel alone and the probability distribution of the measurement result is a Gaussian distribution around the unknown parameter of the input coherent state with a width given by the squeezing parameter. 展开更多
关键词 quantum teleportation coherent states squeezed vacuum states
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Entanglement Properties of Two-Mode Squeezed Coherent States in Radiation Field
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作者 PING Yun-Xia CHENG Ze ZHANG Bo CHENG Zheng-Ze 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第4期1013-1016,共4页
Entanglement properties of two-mode squeezed coherent states in the radiation field &re investigated according to the entanglement criterion [Phys. Rev. Lett. 84 (2000) 2722]. The dependence of entanglement on sque... Entanglement properties of two-mode squeezed coherent states in the radiation field &re investigated according to the entanglement criterion [Phys. Rev. Lett. 84 (2000) 2722]. The dependence of entanglement on squeeze angle and squeeze parameter is discussed. It shows that the system evolves into entangled states and entanglement does not increase persistently with the increase of squeeze angle and squeeze parameter. There only exists a certain squeeze angle in which the entanglement exists continuously. 展开更多
关键词 ENTANGLEMENT two-mode squeezed coherent states radiation field
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