Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner function for the Hermite polynomial state （HP...Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner function for the Hermite polynomial state （HPS）. The tomogram of the HPS is calculated with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics.展开更多
Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner functions for the photon-depleted even and odd...Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner functions for the photon-depleted even and odd coherent states （PDEOCSs）. Moreover, in terms of the Wigner functions with respect to the complex parameter a the nonclassical properties of the PDEOCSs are discussed. The results show that the nonclassicality for the state ｜β, m〉o （or ｜β,m〉e） is more pronounced when m is even （or odd）. According to the marginal distributions of the Wigner functions, the physical meaning of the Wigner functions is given. Further, the tomograms of the PDEOCSs are calculated with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics.展开更多
According to Fan Hu＇s formalism （Fan Hong-Yi and Hu Li-Yun 2009 Opt. Commun. 282 3734） that the tomogram of quantum states can be considered as the module-square of the state wave function in the intermediate coord...According to Fan Hu＇s formalism （Fan Hong-Yi and Hu Li-Yun 2009 Opt. Commun. 282 3734） that the tomogram of quantum states can be considered as the module-square of the state wave function in the intermediate coordinatemomentum representation which is just the eigenvector of the Fresnel quadrature phase, we derive a new theorem for calculating quantum tomogram of density operator, i.e., the tomogram of a density operator p is equal to the marginal integration of the classical Weyl correspondence function of F1pF, where F is the Fresnel operator. Applications of this theorem to evaluating the tomogram of optical chaotic field and squeezed chaotic optical field are presented.展开更多
This paper investigates the decoherence of photo-subtracted squeezed vacuum state （PSSVS） in dissipative channel by describing its statistical properties with time evolution such as Wigner function, Husimi function,...This paper investigates the decoherence of photo-subtracted squeezed vacuum state （PSSVS） in dissipative channel by describing its statistical properties with time evolution such as Wigner function, Husimi function, and tomogram. It first calculates the normalization factor of PSSVS related to Legendre polynomial. After deriving the normally ordered density Operator of PSSVS in dissipative channel, one obtains the explicit analytical expressions of time evolution of PSSVS＇s statistical distribution function. It finds that these statistical distributions loss their non-Gaussian nature and become Gaussian at last in the dissipative environment as expected.展开更多
In this paper, we propose a class of the generalized photon-added coherent states （GPACSs） obtained by repeatedly operating the combination of Bosonie creation and annihilation operatoes on the coherent state. The n...In this paper, we propose a class of the generalized photon-added coherent states （GPACSs） obtained by repeatedly operating the combination of Bosonie creation and annihilation operatoes on the coherent state. The normalization factor of GPACS is related to Hermite polynomial. We also derive the explicit expressions of its statistical properties such as photocount distribution, Wigner function and tomogram and investigate their behaviour as the photon-added number varies graphically. It is found that GPACS is a kind of nonclassical state since Wigner function exhibits the negativity by increasing the photon-added number.展开更多
This paper introduces the generalized excited pair coherent state （GEPCS）. Using the entangled state 〈η〉 representation of Wigner operator, it obtains the Wigner function for the GEPCS. In the ρ-γ phase space, ...This paper introduces the generalized excited pair coherent state （GEPCS）. Using the entangled state 〈η〉 representation of Wigner operator, it obtains the Wigner function for the GEPCS. In the ρ-γ phase space, the variations of the Wigner function distributions with the parameters q, α, k and l are discussed. The tomogram of the GEPCS is calculated with the help of the Radon transform between the Wigner operator and the projection operator of the entangled state ｜η1, η2, τ1, τ2｜. The entangled states ｜η〉 and ｜η1, η2, τ1, τ2〉 provide two good representative space for studying the Wigner functions and tomograms of various two-mode correlated quantum states.展开更多
Using a numerical computational method, quasiprobability distributions of new kinds of even and odd nonlinear coherent states （EONLCS） are investigated. The results show that the distributions of the new even nonlin...Using a numerical computational method, quasiprobability distributions of new kinds of even and odd nonlinear coherent states （EONLCS） are investigated. The results show that the distributions of the new even nonlinear coherent states （NLCS） are distinct from those of the new odd NLCS and imply that the new EONLCS always exhibit some different nonclassical effects. Finally, with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics, the tomograms of the new EONLCS are calculated. This is a new way of obtaining the tomogram function.展开更多
Based on the Fan-Hu＇s formalism, i.e., the tomogram of two-mode quantum states can be considered as the module square of the states＇ wave function in the intermediate representation, which is just the eigenvector of...Based on the Fan-Hu＇s formalism, i.e., the tomogram of two-mode quantum states can be considered as the module square of the states＇ wave function in the intermediate representation, which is just the eigenvector of the Fresnel quadrature phase, we derive a new theorem for calculating the quantum tomogram of two-mode density operators, i.e., the tomogram of a two-mode density operator is equal to the marginal integration of the classical Weyl correspondence function of Fl2pF2, where F2 is the two-mode Fresnel operator. An application of the theorem in evaluating the tomogram of an optical chaotic field is also presented.展开更多
Cryo-electron tomography（cryo-ET） is a cutting-edge technology providing three-dimensional in situ ultra-structural information of macromolecular machineries, organelles, and eukaryotic cells in their native environ...Cryo-electron tomography（cryo-ET） is a cutting-edge technology providing three-dimensional in situ ultra-structural information of macromolecular machineries, organelles, and eukaryotic cells in their native environment at an unprecedented level of detail. Cryo-ET enables the direct observation of dynamic macromolecular architectures of bio-samples in their naturally occurring physiological state, without any harmful artifacts introduced by heavy metal staining, dehydration, and chemical fixation, which occur in traditional transmission electron microscopy. Over decades, cryo-ET has been providing insights into numerous aspects of cellular biology by revealing the pristinely preserved ultra-structures of different cellular components comprising the crowded and complex environment of the cell, thus, bridging the gap between cellular biology and structural biophysics. In this paper, we review the fundamentals of this technique, its recent advances in optics, detection devices, and computational algorithms. The enhancement of our understanding of structural cellular biology by combining these improvements, when integrated with other methods, such as cryo-focused ion beam milling,correlative light and electron microscopy, is discussed via a few examples from research groups worldwide. We also believe that cryo-ET applications in cell biology continue to provide fundamental insights into the field, revolutionizing structural biology itself.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 10574060） and the Natural Science Foundation of Shandong Province of China （Grant No Y2004A09）.
文摘Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner function for the Hermite polynomial state （HPS）. The tomogram of the HPS is calculated with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574060)the Natural Science Foundation of Shandong Province of China (Grant No Y2004A09)
文摘Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner functions for the photon-depleted even and odd coherent states （PDEOCSs）. Moreover, in terms of the Wigner functions with respect to the complex parameter a the nonclassical properties of the PDEOCSs are discussed. The results show that the nonclassicality for the state ｜β, m〉o （or ｜β,m〉e） is more pronounced when m is even （or odd）. According to the marginal distributions of the Wigner functions, the physical meaning of the Wigner functions is given. Further, the tomograms of the PDEOCSs are calculated with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics.
基金Project supported by the Doctoral Scientific Research Startup Fund of Anhui University, China (Grant No. 33190059)the National Natural Science Foundation of China (Grant No. 10874174)
文摘According to Fan Hu＇s formalism （Fan Hong-Yi and Hu Li-Yun 2009 Opt. Commun. 282 3734） that the tomogram of quantum states can be considered as the module-square of the state wave function in the intermediate coordinatemomentum representation which is just the eigenvector of the Fresnel quadrature phase, we derive a new theorem for calculating quantum tomogram of density operator, i.e., the tomogram of a density operator p is equal to the marginal integration of the classical Weyl correspondence function of F1pF, where F is the Fresnel operator. Applications of this theorem to evaluating the tomogram of optical chaotic field and squeezed chaotic optical field are presented.
基金supported by the National Natural Science Foundation of China (Grant No. 10775097)the Key Program Foundation of the Ministry of Education of China (Grant No. 210115)the Research Foundation of the Education Department of Jiangxi Province of China (Grant No. GJJ10097)
文摘This paper investigates the decoherence of photo-subtracted squeezed vacuum state （PSSVS） in dissipative channel by describing its statistical properties with time evolution such as Wigner function, Husimi function, and tomogram. It first calculates the normalization factor of PSSVS related to Legendre polynomial. After deriving the normally ordered density Operator of PSSVS in dissipative channel, one obtains the explicit analytical expressions of time evolution of PSSVS＇s statistical distribution function. It finds that these statistical distributions loss their non-Gaussian nature and become Gaussian at last in the dissipative environment as expected.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10775097 and 10874174)
文摘In this paper, we propose a class of the generalized photon-added coherent states （GPACSs） obtained by repeatedly operating the combination of Bosonie creation and annihilation operatoes on the coherent state. The normalization factor of GPACS is related to Hermite polynomial. We also derive the explicit expressions of its statistical properties such as photocount distribution, Wigner function and tomogram and investigate their behaviour as the photon-added number varies graphically. It is found that GPACS is a kind of nonclassical state since Wigner function exhibits the negativity by increasing the photon-added number.
基金supported by the National Natural Science Foundation of China (Grant No 10574060)the Natural Science Foundation of Shandong Province of China (Grant No Y2004A09)
文摘This paper introduces the generalized excited pair coherent state （GEPCS）. Using the entangled state 〈η〉 representation of Wigner operator, it obtains the Wigner function for the GEPCS. In the ρ-γ phase space, the variations of the Wigner function distributions with the parameters q, α, k and l are discussed. The tomogram of the GEPCS is calculated with the help of the Radon transform between the Wigner operator and the projection operator of the entangled state ｜η1, η2, τ1, τ2｜. The entangled states ｜η〉 and ｜η1, η2, τ1, τ2〉 provide two good representative space for studying the Wigner functions and tomograms of various two-mode correlated quantum states.
基金Project supported by the Natural Science Foundation of Shandong Province of China (Grant No Y2008A23)the Natural Science Foundation of Liaocheng University (Grant No X071049)
文摘Using a numerical computational method, quasiprobability distributions of new kinds of even and odd nonlinear coherent states （EONLCS） are investigated. The results show that the distributions of the new even nonlinear coherent states （NLCS） are distinct from those of the new odd NLCS and imply that the new EONLCS always exhibit some different nonclassical effects. Finally, with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics, the tomograms of the new EONLCS are calculated. This is a new way of obtaining the tomogram function.
基金Project supported by the Doctoral Scientific Research Startup Fund of Anhui University,China(Grant No.33190059)the National Natural Science Foundation of China(Grant No.10874174)the President Foundation of Chinese Academy of Sciences
文摘Based on the Fan-Hu＇s formalism, i.e., the tomogram of two-mode quantum states can be considered as the module square of the states＇ wave function in the intermediate representation, which is just the eigenvector of the Fresnel quadrature phase, we derive a new theorem for calculating the quantum tomogram of two-mode density operators, i.e., the tomogram of a two-mode density operator is equal to the marginal integration of the classical Weyl correspondence function of Fl2pF2, where F2 is the two-mode Fresnel operator. An application of the theorem in evaluating the tomogram of an optical chaotic field is also presented.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0504800)the Pujiang Talent Program(Grant No.17PJ1406700)
文摘Cryo-electron tomography（cryo-ET） is a cutting-edge technology providing three-dimensional in situ ultra-structural information of macromolecular machineries, organelles, and eukaryotic cells in their native environment at an unprecedented level of detail. Cryo-ET enables the direct observation of dynamic macromolecular architectures of bio-samples in their naturally occurring physiological state, without any harmful artifacts introduced by heavy metal staining, dehydration, and chemical fixation, which occur in traditional transmission electron microscopy. Over decades, cryo-ET has been providing insights into numerous aspects of cellular biology by revealing the pristinely preserved ultra-structures of different cellular components comprising the crowded and complex environment of the cell, thus, bridging the gap between cellular biology and structural biophysics. In this paper, we review the fundamentals of this technique, its recent advances in optics, detection devices, and computational algorithms. The enhancement of our understanding of structural cellular biology by combining these improvements, when integrated with other methods, such as cryo-focused ion beam milling,correlative light and electron microscopy, is discussed via a few examples from research groups worldwide. We also believe that cryo-ET applications in cell biology continue to provide fundamental insights into the field, revolutionizing structural biology itself.
