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1.
We show that the newly found complete and orthonormal representation <λ|, which is constructed in terms of guiding centers and canonical momenta of an electron moving in a uniform magnetic field, also helps us to establish a systematic phase operator theory. The unitary phase operator, interpreted as a quantity canonically conjugated to the electron angular momentum, manifestly exhibits in the <λ| representation its phase behavior. As a byproduct, the phase distribution function, in the correct sense of probability in quantum mechanics, can also be defined by the <λ| representation. 相似文献
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Jafari Matehkolaee Mehdi 《中国物理 B》2021,30(8):80301-080301
We investigate the general condition for an operator to be unitary. This condition is introduced according to the definition of the position operator in curved space. In a particular case, we discuss the concept of translation operator in curved space followed by its relation with an anti-Hermitian generator. Also we introduce a universal formula for adjoint of an arbitrary linear operator. Our procedure in this paper is totally different from others, as we explore a general approach based only on the algebra of the operators. Our approach is only discussed for the translation operators in one-dimensional space and not for general operators. 相似文献
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Using the technique of integration within an ordered product of operators we derive some &function operator formulas of photon creation and annihilation operators. Applications of these new formulas in simplifying some Louisell's operator theorems and in discussing the eigenket of creation operator are presented. 相似文献
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SUN Changyou 《Chinese Journal of Lasers》1996,5(2):129-136
TheSqueezingOperatorandtheSqueezedStatesof"Superspace"¥SUNChangyou(DepartmentofPhysics,HeiheTecher'sCollege,Heihe164300)MAAiq... 相似文献
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HAO Xiang ZHU Shi-Qun 《理论物理通讯》2005,44(8)
The canonical quantum teleportation of two-particle arbitrary state is realized by means of phase operator and number operator. The maximally entangled eigenstates between the difference of phase operators and the sum of number operators are considered as the quantum channels. In contrast to the standard quantum teleportation, the different unitary local operation of canonical teleportation can be simplified by a general expression. 相似文献
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HAO Xiang ZHU Shi-Qun 《理论物理通讯》2005,44(2):353-355
The canonical quantum teleportation of two-particle arbitrary state is realized by means of phase operator and number operator. The maximally entangled eigenstates between the difference of phase operators and the sum of number operators are considered as the quantum channels. In contrast to the standard quantum teleportation, the different unitary local operation of canonical teleportation can be simplified by a general expression. 相似文献
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Kyu Hwang Yeon Suk Seong Kim Chung In Um Thomas F. George 《International Journal of Theoretical Physics》2003,42(9):2043-2059
Quantum Hamiltonian systems corresponding to classical systems related by a general canonical transformation are considered. The differential equation to find the unitary operator, which corresponds to the canonical transformation and connects quantum states of the original and transformed systems, is obtained. The propagator associated with their wave functions is found by the unitary operator. Quantum systems related by a linear canonical point transformation are analyzed. The results are tested by finding the wave functions of the under-, critical-, and over-damped harmonic oscillator from the wave functions of the harmonic oscillator, free-particle system, and negative harmonic potential system, using the unitary operator to connect them, respectively. 相似文献
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W.-S. Chung 《International Journal of Theoretical Physics》2002,41(10):1971-1977
The unitary operator of su
q
(n)-covariant oscillator algebra is constructed and two types of q-coherent states are obtained explicitly. 相似文献
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FAN Hong-Yi Hai-Liang 《理论物理通讯》2006,46(4):599-602
We show that the time-dependent two-mode Fresnel operator is just the time-evolutional unitary operator governed by the Hamiltonian composed of quadratic combination of canonical operators in the way of exhibiting SU(1,1) algebra. This is an approach for obtaining the time-dependent Hamiltonian from the preassigned time evolution in classical phase space, an approach which is in contrast to Lewis-Riesenfeld's invariant operator theory of treating timedependent harmonic oscillators. 相似文献
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The operator-norm convergence of the Trotter product formula is known for self-adjoint semigroups with compactness or smallness conditions on the generators involved in this formula. We generalize these two types of results to sectorial generators. 相似文献
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It is known that exp [iλ (Q1P1i/2)] is a unitary single-mode squeezing operator,where Q1,P1 are the coordinate and momentum operators,respectively.In this paper we employ Dirac’s coordinate representation to prove that the exponential operator S n ≡ exp [iλ sum((QiPi+1+Qi+1Pi))) from i=1 to n ],(Qn+1=Q1,Pn+1=P1),is an n-mode squeezing operator which enhances the standard squeezing.By virtue of the technique of integration within an ordered product of operators we derive S n ’s normally ordered expansion and obtain new n-mode squeezed vacuum states,its Wigner function is calculated by using the Weyl ordering invariance under similar transformations. 相似文献
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利用简洁的幺正变换得到双模压缩算符在纠缠态中表示,使用同样的方法可得到双模压缩算符在坐标和动量本征态中的表示。 相似文献
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分析量子条件振幅算子的性质,该算子起一个类似于在经典信息理论中的条件概率的作用.论证表示一个量子双组元系统的条件算子的频谱在局域幺正变换下是不变的,并且表明它的不可分性.证明一个可分态的条件振幅算子不能有一个超过1的本征值.得出一个在von Neumann条件熵的非负性基础上的相关的可分性条件.
关键词:
条件概率
条件振幅算子
von Neumann条件熵
可分性条件 相似文献
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We introduce a new unitary operator U which can engender a squeezing and rotating entangled transformation. The U operator has a concise expression in a new representation in two-mode Fock space. The normally ordered form of U can be derived by using the technique of integration within an ordered product of operators. The fluctuation in quadrature phases for these squeezing-rotating entangled states are analyzed. 相似文献
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多光子非线性过程中的振幅平方压缩 总被引:4,自引:0,他引:4
本文研究了多光子非线性光学过程中的振幅平方压缩,证明了K光子么正算符Sk(z)(K>2)对非真空相干态的作用在—级近似下会产生振幅平方压缩.以及Sk(z)(K>2,K≠4)对真空态的作用不会产生振幅平方压缩.发现4个光子么正算符S4(z)对真空态的作用可以产生振幅平方压缩,这表明振幅平方压缩是一种独立于二阶压缩、反聚束以及亚泊松统计分布的新的光场非经典效应. 相似文献
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描述高自旋弱耦合系统的广义积算符 总被引:1,自引:1,他引:0
本文提出了Z算符与角动量积算符相结合的广义积算符,用于描述高自旋弱耦合系统NMR实验谱。给出了高自旋系统在自旋耦合作用下的演变公式,Z算符在脉冲作用下的变化公式。以氘(D)为例,计算了重聚INEPT,DEPT和同核COSY实验谱,并对计算方法作了讨论。 相似文献
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Unifying the theory of integration within normal-, Weyl- and antinormal-ordering of operators and the s-ordered operator expansion formula of density operators
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By introducing the s-parameterized generalized Wigner operator into phase-space quantum mechanics we invent the technique of integration within s-ordered product of operators(which considers normally ordered,antinormally ordered and Weyl ordered product of operators as its special cases).The s-ordered operator expansion(denoted by...) formula of density operators is derived,which is ρ = 2 1 s ∫ d2βπβ|ρ |β exp { 2 s 1(s|β|2 β a + βa a a) }.The s-parameterized quantization scheme is thus completely established. 相似文献