In quantum mechanics theory one of the basic operator orderings is Q-P and P-Q ordering,where Q and P are the coordinate operator and the momentum operator,respectively.We derive some new fundamental operator identiti...In quantum mechanics theory one of the basic operator orderings is Q-P and P-Q ordering,where Q and P are the coordinate operator and the momentum operator,respectively.We derive some new fundamental operator identities about their mutual reordering.The technique of integration within Q-P ordering and P-Q ordering is introduced.The Q-P ordered and P-Q ordered formulas of the Wigner operator are also deduced which makes arranging the operators in either Q-P or P-Q ordering much more convenient.展开更多
Like the progress made by Dirac that wave function ψ(x) was reformed as x |ψ,where x| is the coordinate representation,we endow the characteristic function χλ = Tr(e λa-λaρ) of density operator ρ with the mean...Like the progress made by Dirac that wave function ψ(x) was reformed as x |ψ,where x| is the coordinate representation,we endow the characteristic function χλ = Tr(e λa-λaρ) of density operator ρ with the meaning of wave function of |ρ in the thermal entangled state η| representation in the doubled Fock space,χλ = η = λ|ρ,where |ρ = ρ|η = 0.We find the time evolution of χλ can then be directly and neatly obtained via this approach.The way of deriving the density operator from η = λ | ρ is also presented.展开更多
By virtue of the coherent state representation and the operator ordering method we find a new approach for transiting Hermite polynomials to Laguerre polynomials. We also derive the new reciprocal relation of Laguerre...By virtue of the coherent state representation and the operator ordering method we find a new approach for transiting Hermite polynomials to Laguerre polynomials. We also derive the new reciprocal relation of Laguerre polynomials ∑n=0 （-1）n （n^l）Ln （x） = x^l/n, n-O and its application in deriving the sum rule of the Wingner function of Fock states is demonstrated. Some new expansion identities about the operator Laguerre polynomial are also derived. This opens a new route of deriving mathematical polynomials formulas by virtute of the quantum mechanical representations and operator ordering technique.展开更多
For entangled three particles one should treat their wave function as a whole.There is no physical meaning talking about the wave function(or Wigner function) for any one of the tripartite,and therefore considering th...For entangled three particles one should treat their wave function as a whole.There is no physical meaning talking about the wave function(or Wigner function) for any one of the tripartite,and therefore considering the entangled Wigner function(Wigner operator) is of necessity.In this paper,we introduce a pair of mutually conjugate tripartite entangled state representations for defining the Wigner operator of entangled tripartite.Its marginal distributions and the Wigner function of the three-mode squeezed vacuum state are presented.Deriving wave function from its corresponding tripartite entangled Wigner function is also discussed.Moreover,through establishing the n-mode entangled state representation,we introduce the n-mode entangled Wigner operator,which would be more generally useful in quantum physics.展开更多
By virtue of the technique of integration within an ordered product of operators we present a new approach to obtain operators' normal ordering. We first put operators into their Weyl ordering through the Weyl-Wig...By virtue of the technique of integration within an ordered product of operators we present a new approach to obtain operators' normal ordering. We first put operators into their Weyl ordering through the Weyl-Wigner quantization scheme, and then we convert the Weyl ordered operators into normal ordering by virtue of the normally ordered form of the Wigner operator.展开更多
By virtue of the technique of integration within an ordered product (IWOP) of operators and the bipartite entangled state representation, we derive some new identities about operator Hermite polynomials in both the si...By virtue of the technique of integration within an ordered product (IWOP) of operators and the bipartite entangled state representation, we derive some new identities about operator Hermite polynomials in both the single-and two-variable cases. We also find a binomial-like theorem between the single-variable Hermite polynomials and the two-variable Hermite polynomials. Application of these identities in deriving new integration formulas, but without really doing the integration in the usual sense, is demonstrated.展开更多
We develop quantum mechanical Dirac ket-bra operator’s integration theory in Q-ordering or P-ordering to multimode case,where Q-ordering means all Qs are to the left of all Ps and P-ordering means all Ps are to the l...We develop quantum mechanical Dirac ket-bra operator’s integration theory in Q-ordering or P-ordering to multimode case,where Q-ordering means all Qs are to the left of all Ps and P-ordering means all Ps are to the left of all Qs.As their applications,we derive Q-ordered and P-ordered expansion formulas of multimode exponential operator e iPlΛlkQk.Application of the new formula in finding new general squeezing operators is demonstrated.The general exponential operator for coordinate representation transformation q1q2→A B C D q1q2is also derived.In this way,much more correpondence relations between classical coordinate transformations and their quantum mechanical images can be revealed.展开更多
By analyzing theoretical scheme of quantum controlling through photon addition,we propose a new optical field whose density operator asρ=λ(1-λ)l:Ll(-λ2aa/1-λ)e-λaa:(here::denotes normal ordering symbol),which is...By analyzing theoretical scheme of quantum controlling through photon addition,we propose a new optical field whose density operator asρ=λ(1-λ)l:Ll(-λ2aa/1-λ)e-λaa:(here::denotes normal ordering symbol),which is named Laguerre-polynomialweighted chaotic state.We show that such state is the solution to the master equation d/dtρ=-κ(aaρ+ρaa-aρa-aρa),describing a diffusion channel,with the initial number state|l l|,andλ=1/(1+κt).This new state is characteristic of possessing photon number l+κt at time t,so the photon number by adjusting the diffusion parameterκcan be controlled.This master equation is solved using the summation method within ordered product of operators and the entangled state representation.The physical difference between the diffusion and the amplitude damping is noted.展开更多
A type of special two-mode squeezed coherent state is constructed which is a characteristic of squeezing and displacing related. The new states take simpler and neater form than the usual two-mode squeezed coherent st...A type of special two-mode squeezed coherent state is constructed which is a characteristic of squeezing and displacing related. The new states take simpler and neater form than the usual two-mode squeezed coherent states, and also possess a completeness relation. It is expected that experimentalists woking on quantum optics should fabricate such a type of squeezed coherent optical field.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.11175113)
文摘In quantum mechanics theory one of the basic operator orderings is Q-P and P-Q ordering,where Q and P are the coordinate operator and the momentum operator,respectively.We derive some new fundamental operator identities about their mutual reordering.The technique of integration within Q-P ordering and P-Q ordering is introduced.The Q-P ordered and P-Q ordered formulas of the Wigner operator are also deduced which makes arranging the operators in either Q-P or P-Q ordering much more convenient.
基金supported by the National Natural Science Foundation of China (Grant No. 11175113)
文摘Like the progress made by Dirac that wave function ψ(x) was reformed as x |ψ,where x| is the coordinate representation,we endow the characteristic function χλ = Tr(e λa-λaρ) of density operator ρ with the meaning of wave function of |ρ in the thermal entangled state η| representation in the doubled Fock space,χλ = η = λ|ρ,where |ρ = ρ|η = 0.We find the time evolution of χλ can then be directly and neatly obtained via this approach.The way of deriving the density operator from η = λ | ρ is also presented.
基金supported by the National Natural Science Foundation of China (Grant No. 10874174)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20070358009)
文摘By virtue of the coherent state representation and the operator ordering method we find a new approach for transiting Hermite polynomials to Laguerre polynomials. We also derive the new reciprocal relation of Laguerre polynomials ∑n=0 （-1）n （n^l）Ln （x） = x^l/n, n-O and its application in deriving the sum rule of the Wingner function of Fock states is demonstrated. Some new expansion identities about the operator Laguerre polynomial are also derived. This opens a new route of deriving mathematical polynomials formulas by virtute of the quantum mechanical representations and operator ordering technique.
基金supported by the Postdoctoral Science Foundation of Jiangsu Province (Grant No.1202012B)the Research Fund for Advanced Talents of Jiangsu University (Grant No.1281190029)
文摘For entangled three particles one should treat their wave function as a whole.There is no physical meaning talking about the wave function(or Wigner function) for any one of the tripartite,and therefore considering the entangled Wigner function(Wigner operator) is of necessity.In this paper,we introduce a pair of mutually conjugate tripartite entangled state representations for defining the Wigner operator of entangled tripartite.Its marginal distributions and the Wigner function of the three-mode squeezed vacuum state are presented.Deriving wave function from its corresponding tripartite entangled Wigner function is also discussed.Moreover,through establishing the n-mode entangled state representation,we introduce the n-mode entangled Wigner operator,which would be more generally useful in quantum physics.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10775097 and 10947017/A05)the Specialized Research Fund for the Doctorial Progress of Higher Education of China (GrantNo. 20070358009)
文摘By virtue of the technique of integration within an ordered product of operators we present a new approach to obtain operators' normal ordering. We first put operators into their Weyl ordering through the Weyl-Wigner quantization scheme, and then we convert the Weyl ordered operators into normal ordering by virtue of the normally ordered form of the Wigner operator.
基金supported by the National Natural Science Foundation of China (Grant Nos.10775097,11074190 and 10947017/A05)the specialized research fund for the Doctorial Progress of Higher Education of China (Grant No.20070358009)
文摘By virtue of the technique of integration within an ordered product (IWOP) of operators and the bipartite entangled state representation, we derive some new identities about operator Hermite polynomials in both the single-and two-variable cases. We also find a binomial-like theorem between the single-variable Hermite polynomials and the two-variable Hermite polynomials. Application of these identities in deriving new integration formulas, but without really doing the integration in the usual sense, is demonstrated.
基金supported by the National Natural Science Foundation of China (Grant No. 11175113)
文摘We develop quantum mechanical Dirac ket-bra operator’s integration theory in Q-ordering or P-ordering to multimode case,where Q-ordering means all Qs are to the left of all Ps and P-ordering means all Ps are to the left of all Qs.As their applications,we derive Q-ordered and P-ordered expansion formulas of multimode exponential operator e iPlΛlkQk.Application of the new formula in finding new general squeezing operators is demonstrated.The general exponential operator for coordinate representation transformation q1q2→A B C D q1q2is also derived.In this way,much more correpondence relations between classical coordinate transformations and their quantum mechanical images can be revealed.
基金supported by the National Natural Science Foundation of China(Grant Nos.11175113 and 11264018)the Natural Science Foundation of Jiangxi Province of China(Grant No 20132BAB212006)
文摘By analyzing theoretical scheme of quantum controlling through photon addition,we propose a new optical field whose density operator asρ=λ(1-λ)l:Ll(-λ2aa/1-λ)e-λaa:(here::denotes normal ordering symbol),which is named Laguerre-polynomialweighted chaotic state.We show that such state is the solution to the master equation d/dtρ=-κ(aaρ+ρaa-aρa-aρa),describing a diffusion channel,with the initial number state|l l|,andλ=1/(1+κt).This new state is characteristic of possessing photon number l+κt at time t,so the photon number by adjusting the diffusion parameterκcan be controlled.This master equation is solved using the summation method within ordered product of operators and the entangled state representation.The physical difference between the diffusion and the amplitude damping is noted.
文摘A type of special two-mode squeezed coherent state is constructed which is a characteristic of squeezing and displacing related. The new states take simpler and neater form than the usual two-mode squeezed coherent states, and also possess a completeness relation. It is expected that experimentalists woking on quantum optics should fabricate such a type of squeezed coherent optical field.
