共查询到19条相似文献,搜索用时 140 毫秒
1.
We have constructed a new kind of two-mode bosonic realization of SU(1,1) Lie algebra, on the basis of which the SU(1,1) generalized coherent states in the two-mode Fock space are derived. These two-mode SU(1,1) coherent states, which are called uncorrelated two-mode SU(1,1) coherent states, include three special cases. For these states, we study the mean photon number distribution and their non-classical properties, which are photon anti-bunching, violations of Cauchy-Schwarz inequality and two-mode squeezing. 相似文献
2.
Algebraic and group treatments to nonlinear displaced number states and their nonclassicality features:A new approach 下载免费PDF全文
《中国物理 B》2015,(6)
Recently,nonlinear displaced number states(NDNSs) have been manually introduced,in which the deformation function f(n) has been artificially added to the previously well-known displaced number states(DNSs).Indeed,just a simple comparison has been performed between the standard coherent state and nonlinear coherent state for the formation of NDNSs.In the present paper,after expressing enough physical motivation of our procedure,four distinct classes of NDNSs are presented by applying algebraic and group treatments.To achieve this purpose,by considering the DNSs and recalling the nonlinear coherent states formalism,the NDNSs are logically defined through an algebraic consideration.In addition,by using a particular class of Gilmore–Perelomov-type of SU(1,1) and a class of SU(2) coherent states,the NDNSs are introduced via group-theoretical approach.Then,in order to examine the nonclassical behavior of these states,sub-Poissonian statistics by evaluating Mandel parameter and Wigner quasi-probability distribution function associated with the obtained NDNSs are discussed,in detail. 相似文献
3.
Phase sensitivity of two nonlinear interferometers with inputting entangled coherent states 下载免费PDF全文
We investigate the phase sensitivity of the SU(1,1) interfereometer [SU(1,1)I] and the modified Mach–Zehnder interferometer(MMZI) with the entangled coherent states(ECS) as inputs. We consider the ideal case and the situations in which the photon losses are taken into account. We find that, under ideal conditions, the phase sensitivity of both the MMZI and the SU(1,1)I can beat the shot-noise limit(SNL) and approach the Heisenberg limit(HL). In the presence of photon losses, the ECS can beat the coherent and squeezed states as inputs in the SU(1,1)I, and the MMZI is more robust against internal photon losses than the SU(1,1)I. 相似文献
4.
《理论物理通讯》2017,(6)
By representing a quantum state and its evolution with the Majorana stars on the Bloch sphere, the Majorana representation provides us an intuitive way to study a physical system with SU(2) symmetry. In this work,based on coherent states, we propose a method to establish the generalization of Majorana representation for a general symmetry. By choosing a generalized coherent state as a reference state, we give a more general Majorana representation for both finite and infinite systems and the corresponding star equations are given. Using this method, we study the squeezed vacuum states for three different symmetries, Heisenberg–Weyl, SU(2) and SU(1,1), and express the effect of squeezing parameter on the distribution of stars. Furthermore, we also study the dynamical evolution of stars for an initial coherent state driven by a nonlinear Hamiltonian, and find that at a special time point, the stars are distributed on two orthogonal large circles. 相似文献
5.
BCS Ground State and XXZ Antiferromagnetic Model as SU(2),SU(1,1) Coherent States:AN Algebraic Diagonalization Method 总被引:1,自引:0,他引:1
XIEBing_Hao ZHANGHong-Biao 《理论物理通讯》2002,37(3):292-296
An algebraic diagonalization method is proposed.As two examples,the Hamiltonians of BCS ground state under mean-field approximation and XXZ antiferromagnetic model in linear spin-wave frame have been diagonalized by using SU(2),SU(1,1) Lie algebraic method,respectively.Meanwhile,the eignenstates of the above two models are revealed to be SU(2),SU(1,1) coherent states,respectively,The relation between the usual Bogoliubov-Valatin transformation and the algebraic method in a special case is also discussed. 相似文献
6.
We Construct and SU(1,1)coherent state for hydrogen,we discuss its properties,and we give the energy distribution law of the atom.The coherent state may be used to describe the atomic states of the discrete spectrum. 相似文献
7.
WANGJi-Suo LIUTang-Kun FENGJian SUNJin-Zuo 《理论物理通讯》2004,42(3):419-424
In our preceding work, a class of k-quantum nonlinear coherent states, i.e., the k eigenstates of the powers B^^k (k≥3) of the annihilation operator B^ =a^ 1/f(N^) of f-oscillators, are introduced. In this paper, we introduce a new kind of higher-order squeezing and an antibunching effect. The quantum statistical properties of the k states are studied. The result shows that the M-th order [M=(n 1/2)k; n=0, 1,...] squeezing effects exist in all of the k states when k is even. There is the antibunching effect in all of the k states. 相似文献
8.
In our preceding work, a class of k-quantum nonlinear coherent states, i.e., the k eigenstates of the powersBk (k ≥ 3) of the annihilation operator B=-a1/f(N) of f-oscillators, are introduced. In this paper, we introduce a newkind of higher-order squeezing and an antibunching effect. The quantum statistical properties of the k states are studied.The result shows that the M-th order [M = (n 1/2)k; n = 0, 1,...] squeezing effects exist in all of the k states when kis even. There is the antibunching effect in all of the k states. 相似文献
9.
S.M. Nagiyev E.I. Jafarov M.Y. Efendiyev 《理论物理通讯》2008,49(2):315-318
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. 相似文献
10.
Quantum entanglement in the system of a moving V-type three-level atom interacting with the SU(1,1)-related coherent fields 下载免费PDF全文
In a system with a moving V-type three-level atom interacting with
the SU(1,1)-related coherent fields,
we investigate the entanglement between the moving three-level atom
and the SU(1,1)-related coherent fields by
using the quantum-reduced entropy, and that
between the SU(1,1)-related
coherent fields by using the quantum relative
entropy of entanglement. It is shown that the two kinds of entanglement
are dependent on the atomic motion and
exhibit the periodic evolution with a
period of 2π/p. The maximal atom--field qutrit entanglement
state can be prepared, and the entanglement preservation
of the SU(1,1)-related coherent fields
can be realized in the interacting process
via the appropriate selection of system
parameters and interaction time. 相似文献
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13.
Interaction of two two-level atoms with SU(1,1)coherent states¥SONGTongqiang;FENGJian;WANGWenzheng;XUJingzhi(l)InstitufeofOpt... 相似文献
14.
Adding a U(1) symmetry breaking term V1/2 a(λ1a0+λ*1a8224;0)+V1/2(λ2b0+λ*2b8224;0) to Bogoliubov's truncated Hamiltonian HB for a weakly interacting coupled Bose system, by using the mean-field approximation rather than the c-number approximation, we find that, via a Feshbach resonance at zero temperature, the states of the coupled Bose system are generalized SU(1,1) × SU(1,1) coherent states. The Bose-Einsteincondensation occurs in response to the spontaneous U(1) symmetry breaking. 相似文献
15.
We present a kind of new coherent states associated with the Lie superalgebra SU(2/1), and discuss their properties in detail. We also evaluate the matrix elements of the SU(2/1) generators in the coherent state representations and obtain differential realizations of the SU(2/1) algebra in the coherent state space. The differential realizations may be useful for the study of the quasi-exactly solvable problems in the quantum mechanics. 相似文献
16.
两参数变形量子代数SU(1,1)q,s的相干态及其性质 总被引:1,自引:1,他引:0
利用SU(1,1)q,s量子代数的两参数变形振子构造出归一化的SU(1,1)q,s相干态,证明了SU(1,1)q,s量子代数的表示基是正交的,并讨论了它的相干态的归一性和完备性。指出(SU(1,1)q,s相干态的相干性受参数q、s的影响。 相似文献
17.
The coherent-state basis is constructed for symmetric representations of the groups SU(N) and SU(N, 1) and its properties are studied. The evolution of coherent states is considered. A relationship between the SU(N) coherent states and the Glauber coherent states is established.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 83–89, January, 1990. 相似文献
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19.
A new kind of k-quantum nonlinear coherent states, i.e., the k eigenstates of the
k-th power $\hat{B}^{k}$ (k≥3) of the
generalized annihilation operator $\hat{B}=\hat{a}\frac1{f(\hat{N})}$
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. 相似文献