The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A c...The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A compact expression for the Wigner function is also derived analytically by using the Weyl-ordered operator invariance under similar transformations. Especially, the nonclassicality is discussed in terms of the negativity of the Wigner function. Then violations of Bell's inequality for the two-variable Hermite polynomial state are studied.展开更多
Using the entangled state representation, we convert a two-mode squeezed number state to a Hermite polynomial excited squeezed vacuum state. We first analytically derive the photon number distribution of the two-mode ...Using the entangled state representation, we convert a two-mode squeezed number state to a Hermite polynomial excited squeezed vacuum state. We first analytically derive the photon number distribution of the two-mode squeezed thermal states. It is found that it is a Jacobi polynomial; a remarkable result. This result can be directly applied to obtaining the photon number distribution of non-Gaussian states generated by subtracting from (adding to) two-mode squeezed thermal states.展开更多
We investigate the nonclassical properties of the photon-added-then-subtracted coherent squeezed state (PASCSS) via the sub-Poissonian statistics, the photon-number distribution, and the negativity of the Wigner fun...We investigate the nonclassical properties of the photon-added-then-subtracted coherent squeezed state (PASCSS) via the sub-Poissonian statistics, the photon-number distribution, and the negativity of the Wigner function. It is found that the PASSCS is a superposition state of D(β)S(ζ)|0〉, D(β)S(ζ)|1〉, and D(β)S(ζ)|2〉. We find that the Mandel Q parameter, the photon-number distribution, and the negative volume of the Wigner function of the PASCSS are all periodic functions of the compound Ф - 0/2 with a period π involved with squeezing and displacement parameteTs.展开更多
By virtue of the new technique of performing integration over Dirac's ket-bra operators, we ex- plore quantum optical version of classical optical transformations such as optical Fresnel transform, Hankel transform, ...By virtue of the new technique of performing integration over Dirac's ket-bra operators, we ex- plore quantum optical version of classical optical transformations such as optical Fresnel transform, Hankel transform, fractional Fourier transform, Wigner transform, wavelet transform and Fresnel- Hadmard combinatorial transform etc. In this way one may gain benefit for developing classical optics theory from the research in quantum optics, or vice-versa. We cannot only find some new quantum mechanical unitary operators which correspond to the known optical transformations, de- riving a new theorem for calculating quantum tomogram of density operators, but also can reveal some new classical optical transformations. For examples, we find the generalized Fresnel opera- tor (GFO) to correspond to the generalized Fresnel transform (GFT) in classical optics. We derive GFO's normal product form and its canonical coherent state representation and find that GFO is the loyal representation of symplectic group multiplication rule. We show that GFT is just the transformation matrix element of GFO in the coordinate representation such that two successive GFTs is still a GFT. The ABCD rule of the Gaussian beam propagation is directly demonstrated in the context of quantum optics. Especially, the introduction of quantum mechanical entangled state representations opens up a new area in finding new classical optical transformations. The complex wavelet transform and the condition of mother wavelet are studied in the context of quantum op- tics too. Throughout our discussions, the coherent state, the entangled state representation of the two-mode squeezing operators and the technique of integration within an ordered product (IWOP) of operators are fully used. All these have confirmed Dirac's assertion: "...for a quantum dynamic system that has a classical analogue, unitary transformation in the quantum theory is the analogue of contact transformation in the classical theory".展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 11047133)the Natural Science Foundation of Jiangxi Province of China (Grant No. 2010GQW0027)the Research Foundation of the Education Department of Jiangxi Province of China (Grant No. GJJ11390)
文摘The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A compact expression for the Wigner function is also derived analytically by using the Weyl-ordered operator invariance under similar transformations. Especially, the nonclassicality is discussed in terms of the negativity of the Wigner function. Then violations of Bell's inequality for the two-variable Hermite polynomial state are studied.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11047133, 60978009, and 10774088)the Major Research Plan of the National Natural Science Foundation of China (Grant No. 91121023)+2 种基金the "973" Project (Grant No. 2011CBA00200)the Natural Science Foundation of Jiangxi Province of China (No. 2010GQW0027)the Sponsored Program for Cultivating Youths of Outstanding Ability in Jiangxi Normal University
文摘Using the entangled state representation, we convert a two-mode squeezed number state to a Hermite polynomial excited squeezed vacuum state. We first analytically derive the photon number distribution of the two-mode squeezed thermal states. It is found that it is a Jacobi polynomial; a remarkable result. This result can be directly applied to obtaining the photon number distribution of non-Gaussian states generated by subtracting from (adding to) two-mode squeezed thermal states.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11264018)the Natural Science Foundation of Jiangxi Province of China (Grant No. 2010GQW0027)+1 种基金the Key Program Foundation of Ministry of Education of China (Grant No. 210115)the Sponsored Program for Cultivating Youths of Outstanding Ability in Jiangxi Normal University,China
文摘We investigate the nonclassical properties of the photon-added-then-subtracted coherent squeezed state (PASCSS) via the sub-Poissonian statistics, the photon-number distribution, and the negativity of the Wigner function. It is found that the PASSCS is a superposition state of D(β)S(ζ)|0〉, D(β)S(ζ)|1〉, and D(β)S(ζ)|2〉. We find that the Mandel Q parameter, the photon-number distribution, and the negative volume of the Wigner function of the PASCSS are all periodic functions of the compound Ф - 0/2 with a period π involved with squeezing and displacement parameteTs.
文摘By virtue of the new technique of performing integration over Dirac's ket-bra operators, we ex- plore quantum optical version of classical optical transformations such as optical Fresnel transform, Hankel transform, fractional Fourier transform, Wigner transform, wavelet transform and Fresnel- Hadmard combinatorial transform etc. In this way one may gain benefit for developing classical optics theory from the research in quantum optics, or vice-versa. We cannot only find some new quantum mechanical unitary operators which correspond to the known optical transformations, de- riving a new theorem for calculating quantum tomogram of density operators, but also can reveal some new classical optical transformations. For examples, we find the generalized Fresnel opera- tor (GFO) to correspond to the generalized Fresnel transform (GFT) in classical optics. We derive GFO's normal product form and its canonical coherent state representation and find that GFO is the loyal representation of symplectic group multiplication rule. We show that GFT is just the transformation matrix element of GFO in the coordinate representation such that two successive GFTs is still a GFT. The ABCD rule of the Gaussian beam propagation is directly demonstrated in the context of quantum optics. Especially, the introduction of quantum mechanical entangled state representations opens up a new area in finding new classical optical transformations. The complex wavelet transform and the condition of mother wavelet are studied in the context of quantum op- tics too. Throughout our discussions, the coherent state, the entangled state representation of the two-mode squeezing operators and the technique of integration within an ordered product (IWOP) of operators are fully used. All these have confirmed Dirac's assertion: "...for a quantum dynamic system that has a classical analogue, unitary transformation in the quantum theory is the analogue of contact transformation in the classical theory".