共查询到20条相似文献,搜索用时 93 毫秒
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参数化玻色湮灭算符高次幂的本征态及其量子起伏规律 总被引:1,自引:1,他引:0
以参数化方式「y」=(q^y-1)/(q-1)定义q玻色湮灭算符aq,生成相应的q相干态,找出能产生并保持这类q相干态的体系的哈密顿量。研究了α^kq的正交归一本征态的数学结构和量子起伏性质,发现这些本征态中只有偶q相干态存在通常的压缩效应,并且当q〈1时,场的两个正交分量在各态中的量子起估可以同时有小于相干态的最小不确定度,有q压缩效应。 相似文献
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利用参量相关的Bogoliubov变换公式,导出描写Paul阱系统含时哈密顿的精确本征态--广义SU(1,1)相干态,讨论了关于这些态的粒子数涨落和平方振幅压缩特性。 相似文献
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根据量子力学中态的线性叠加原理,构造了由多模真空态、多模相干态、多模相干态的相反态和多模虚相干态的线性叠加所组成的真空场注入四态叠加多模纠缠态(即4SMES)光场.利用多模压缩态理论研究了上述光场中广义电场分量的等幂次高次和压缩特性.结果发现:真空场注入4SMES光场是一种典型的四态叠加多模非经典光场;在一定条件下,该光场的广义电场分量可呈现出周期性变化的广义非线性等幂4m+2次和压缩效应. 相似文献
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根据量子力学中态的线性叠加原理,构造了由多模真空态、多模相干态、多模相干态的相反态和多模虚相干态的线性叠加所组成的真空场注入四态叠加多模纠缠态(即4SMES)光场.利用多模压缩态理论研究了上述光场中广义电场分量的等幂次高次和压缩特性.结果发现:真空场注入4SMES光场是一种典型的四态叠加多模非经典光场;在一定条件下,该光场的广义电场分量可呈现出周期性变化的广义非线性等幂4m+2次和压缩效应. 相似文献
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基于声子相干态功效和计及声子压缩态非经典效应,研究了电子-磁振子和电子-声子相互作用对一维介观环持续电流的影响. 与自由环比较,由于电子-磁振子相互作用,持续电流的振幅呈现指数减小. 对于正常态电子,电子-声子相互作用导致持续电流以Debye-Waller(D-W)因子衰减.但是计入跳步电子-单声子相干态关联效应导致系统本征态能量大幅度下降,从而持续电流In有大幅度增加.另一方面计入双声子相干态行为,由于声子压缩态效应压缩电子-相干(态)声子弹性散射行为,导致电子绕环运
关键词:
持续电流
电子-声子相互作用
声子相干态
声子压缩态效应 相似文献
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SU(2) andSU(1,1) algebra eigenstates: A unified analytic approach to coherent and intelligent states
Constantin Brif 《International Journal of Theoretical Physics》1997,36(7):1651-1682
We introduce the concept of algebra eigenstates which are defined for an arbitrary Lie group as eigenstates of elements of
the corresponding complex Lie algebra. We show that this concept unifies different definitions of coherent states associated
with a dynamical symmetry group. On the one hand, algebra eigenstates include different sets of Perelomov's generalized coherent
states. On the other hand, intelligent states (which are squeezed states for a system of general symmetry) also form a subset
of algebra eigenstates. We develop the general formalism and apply it to theSU(2) andSU(1,1) simple Lie groups. Complete solutions to the general eigenvalue problem are found in both cases by a method that employs
analytic representations of the algebra eigenstates. This analytic method also enables us to obtain exact closed expressions
for quantum statistical properties of an arbitrary algebra eigenstate. Important special cases such as standard coherent states
and intelligent states are examined and relations between them are studied by using their analytic representations. 相似文献
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We present a proposal for protecting states against decoherence, based on the engineering of pointer states. We apply this procedure to the vibrational motion of a trapped ion, and show how to protect qubits, squeezed states, approximate phase eigenstates, and superpositions of coherent states. 相似文献
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JINShuo XIEBing-Hao ZHANGHong-Biao GEMo-Lin 《理论物理通讯》2004,42(5):681-688
Some analytical solutions of generalized two-mode harmonic oscillators model are obtained by utilizing an algebraic diagonalization method. We find two types of eigenstates which are formulated as extended SU(1,1), SU(2) squeezed number states respectively. Some statistical properties of these states are also discussed. 相似文献
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Some analytical solutions of generalized two-mode harmonic oscillators model are obtained by utilizing an algebraic diagonalization method. We find two types of eigenstates which are formulated as extended SU(1,1), SU(2)squeezed number states respectively. Some statistical properties of these states are also discussed. 相似文献
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Alfred Wünsche 《Annalen der Physik》1992,504(3):181-197
The eigenvalue problem for arbitrary linear combinations kα + μα? of a boson annihilation operator α and a boson creation operator α? is solved. It is shown that these operators possess nondegenerate eigenstates to arbitrary complex eigenvalues. The expansion of these eigenstates into the basic set of number states | n >, (n = 0, 1, 2, …), is found. The eigenstates are normalizable and are therefore states of a Hilbert space for | ζ | < 1 with ζ ? μ/k and represent in this case squeezed coherent states of minimal uncertainty product. They can be considered as states of a rigged Hilbert space for | ζ | ? 1. A completeness relation for these states is derived that generalizes the completeness relation for the coherent states | α 〉. Furthermore, it is shown that there exists a dual orthogonality in the entire set of these states and a connected dual completeness of the eigenstates on widely arbitrary paths over the complex plane of eigenvalues. This duality goes over into a selfduality of the eigenstates of the hermitian operators kα + k* α? to real eigenvalues. The usually as nonexistent considered eigenstates of the boson creation operator α? are obtained by a limiting procedure. They belong to the most singular case among the considered general class of eigenstates with ζ ? μ/k as a parameter. 相似文献
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本文利用推广的Jaynes-Cummings模型描述N个二能级原子的超辐射,得到了辐射场的二阶关联函数的一般表达式。并进而用于缓变耦合情况,着重研究了共振情况下由超泊松光场演化成亚泊松光场的初始条件。作为例子,讨论了推广相干态及压缩相干态的演化条件。最后提出了利用相干态光场观察亚泊松光子统计的实验建议。 相似文献
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得到了参量放大器哈密顿量与广义双模压缩算符共同本征的双模压缩数态。提出了压缩荷与压缩对称性的概念来解释哈密顿量在由广义压缩算符生成的一维么正群变换下的不变性。 相似文献
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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
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The phase properties of the superposed squeezed states are studied. The superposed squeezed states are obtained by inserting
two squeezers in a Mach-Zehnder interferometer one for each arm. The visibility of the states as a measure of the coherence
of the generated photons in the nonlinear interferometer is analyzed. And the mean-square phase fluctuations are also considered
to analyze the phase properties of the superposed squeezed states. The quantities are obtained as a function of gain and the
input phase, when the amplified input is a coherent state, a number state, a thermal state, a displaced number state, or a
coherent thermal state. 相似文献
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A.-S. F. Obada G. M. Abd Al-Kader 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(1):189-198
The nonlinear extensions of the single-mode squeezed vacuum and
squeezed coherent states are studied. We have constructed the
nonlinear squeezed states (NLSS's) realization of
SU(1,1) Lie algebra. Two cases of this realization are
considered for unitary and non-unitary deformation operator
function. The nonlinear squeezed coherent states (NLSCS's)
are defined and special cases of these states are obtained.
Some nonclassical properties of these states are discussed. The
s-parameterized characteristic function and various moments are
calculated. The Glauber second-order coherence function is
calculated. The squeezing properties of the NLSCS's are studied.
Analytical and numerical results for the quadrature component
distributions for the NLSCS's are presented. A generation scheme for
NLSCS's using the trapped ions centre-of-mass motion approach is
proposed. 相似文献