This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseud...This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseudoclassical states. According to the analysis, it is found that the superposition state of two coherent states with their phase differences π/2 and 3π/2, and the superposition state of two pseudoclassical states both do exhibit the amplitude-squared squeezing. Also, some specific states are found to exhibit even stronger squeezing effects when relative phase of the superposition is equal to the average photon number. Amplitude-squared squeezing is dependent on the difference in phase between two coherent states.展开更多
We study the quantum fluctuations and the amplitude squeezing of a weakly interacting Bose system withspontaneous U(1) symmetry breaking.It is found that this system can exhibit amplitude squeezing.
We investigate how an optical squeezed chaotic field（SCF） evolves in an amplitude dissipation channel. We have used the integration within ordered product of operators technique to derive its evolution law. We also ...We investigate how an optical squeezed chaotic field（SCF） evolves in an amplitude dissipation channel. We have used the integration within ordered product of operators technique to derive its evolution law. We also show that the density operator of SCF can be viewed as a generating field of the squeezed number state.展开更多
Using the thermal-entangled state representation and the operator-ordering method, we investigate Wigner function(WF) for the squeezed negative binomial state(SNBS) and the analytical evolution law of density operator...Using the thermal-entangled state representation and the operator-ordering method, we investigate Wigner function(WF) for the squeezed negative binomial state(SNBS) and the analytical evolution law of density operator in the amplitude decay channel.The results show that the analytical WF is related to the square of the module of single-variable Hermite polynomials, which leads to a new two-variable special function and its generating function, and the parameters s and γplay opposite roles in the WF distributions.Besides, after undergoing this channel, the initial pure SNBS evolves into a new mixed state related to two operator Hermite polynomials within normal ordering, and fully loses its nonclassicality and decays to vacuum at long decay time.展开更多
We explore how a two-mode squeezed vacuum state sechθeab tanh θ[00） evolves when it undergoes a single- mode amplitude dissipative channel with rate of decay k. We find that in this process not only the squeezing p...We explore how a two-mode squeezed vacuum state sechθeab tanh θ[00） evolves when it undergoes a single- mode amplitude dissipative channel with rate of decay k. We find that in this process not only the squeezing parameter decreases, tanhθ → e-kt tanh θ, but also the second-mode vacuum state evolves into a chaotic state exp{bbln[（1 - e-2kt） tanh2 θ]}. The outcome state is no more a pure state, but an entangled mixed state.展开更多
The result of one-mode quadrature-amplitude measurement for some generalized two-mode squeezed states has been studied by virtue of the entangled state representation of the corresponding two-mode squeezing operators....The result of one-mode quadrature-amplitude measurement for some generalized two-mode squeezed states has been studied by virtue of the entangled state representation of the corresponding two-mode squeezing operators. We find that the remaining fleld-mode simultaneously collapses to the single-mode squeezed state with more stronger squeezing. The measurement result caused by a single-mode squeezed state projector is also calculated, which indicates quantum entanglement in squeezing.展开更多
By virtue of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of ...By virtue of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of squeezed operators and f-analogues of squeezed one-photon states, which are quite different from ones constructed by Song and Fan （Phys. Lett. A 294 （2002） 66）. Subsequently, some nonclassical properties of the states are investigated in detail.展开更多
Extending the recent work completed by Fan et al. [Front. Phys. 9（1）, 74 （2014）] to a two-mode case, we investigate how a two-mode squeezed vacuum evolves when it undergoes a two-mode amplitude dissipative channel...Extending the recent work completed by Fan et al. [Front. Phys. 9（1）, 74 （2014）] to a two-mode case, we investigate how a two-mode squeezed vacuum evolves when it undergoes a two-mode amplitude dissipative channel, with the same decay rate ~, using the continuous-variable entangled state approach. Our analytical results show that the initial pure-squeezed vacuum state evolves into a definite mixed state with entanglement and squeezing, decaying over time as a result of amplitude decay. We also investigate the time evolutions of the photon number distribution, the Wigner function, and the optical tomogram in this channel. Our results indicate that the evolved photon number distribution is related to Jacobi polynomials, the Wigner function has a standard Gaussian distribution （corresponding to the vacuum） at long periods, losing its nonclassicality due to amplitude decay, and a larger squeezing leads to a longer decay time.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos 10674038 and 10604042)National Basic Research Program of China (Grant No 2006CB302901)
文摘This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseudoclassical states. According to the analysis, it is found that the superposition state of two coherent states with their phase differences π/2 and 3π/2, and the superposition state of two pseudoclassical states both do exhibit the amplitude-squared squeezing. Also, some specific states are found to exhibit even stronger squeezing effects when relative phase of the superposition is equal to the average photon number. Amplitude-squared squeezing is dependent on the difference in phase between two coherent states.
基金The project supported by National Natural Science Foundation of China under Grant No.10574060the Natural Science Foundation of Beijing under Grant No.1072010
文摘We study the quantum fluctuations and the amplitude squeezing of a weakly interacting Bose system withspontaneous U(1) symmetry breaking.It is found that this system can exhibit amplitude squeezing.
基金Project supported by the National Natural Science Foundation of China(Grant No.10574647)the Natural Science Foundation of Shandong Province,China(Grant No.Y2008A16)the University Experimental Technology Foundation of Shandong Province of China(Grant No.S04W138)
文摘We investigate how an optical squeezed chaotic field（SCF） evolves in an amplitude dissipation channel. We have used the integration within ordered product of operators technique to derive its evolution law. We also show that the density operator of SCF can be viewed as a generating field of the squeezed number state.
基金Project supported by the National Natural Science Foundation of China(Grant No.11347026)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2016AM03 and ZR2017MA011)
文摘Using the thermal-entangled state representation and the operator-ordering method, we investigate Wigner function(WF) for the squeezed negative binomial state(SNBS) and the analytical evolution law of density operator in the amplitude decay channel.The results show that the analytical WF is related to the square of the module of single-variable Hermite polynomials, which leads to a new two-variable special function and its generating function, and the parameters s and γplay opposite roles in the WF distributions.Besides, after undergoing this channel, the initial pure SNBS evolves into a new mixed state related to two operator Hermite polynomials within normal ordering, and fully loses its nonclassicality and decays to vacuum at long decay time.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11047133 and 10647133)the Natural Science Foundation of Jiangxi Province of China (Grant Nos. 2009GQS0080 and 2010GQW0027)the Research Foundation of the Education Department of Jiangxi Province of China (Grant Nos. GJJ11339 and GJJ10097)
文摘We explore how a two-mode squeezed vacuum state sechθeab tanh θ[00） evolves when it undergoes a single- mode amplitude dissipative channel with rate of decay k. We find that in this process not only the squeezing parameter decreases, tanhθ → e-kt tanh θ, but also the second-mode vacuum state evolves into a chaotic state exp{bbln[（1 - e-2kt） tanh2 θ]}. The outcome state is no more a pure state, but an entangled mixed state.
文摘The result of one-mode quadrature-amplitude measurement for some generalized two-mode squeezed states has been studied by virtue of the entangled state representation of the corresponding two-mode squeezing operators. We find that the remaining fleld-mode simultaneously collapses to the single-mode squeezed state with more stronger squeezing. The measurement result caused by a single-mode squeezed state projector is also calculated, which indicates quantum entanglement in squeezing.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574060） and the Natural Science Foundation of Shandong Province, China （Grant No Y2004A09）.
文摘By virtue of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of squeezed operators and f-analogues of squeezed one-photon states, which are quite different from ones constructed by Song and Fan （Phys. Lett. A 294 （2002） 66）. Subsequently, some nonclassical properties of the states are investigated in detail.
基金We are grateful to Prof. Hsi-Sheng Goan for valuable support during writing the paper. The project was supported by the National Natural Science Foundation of China （Grant No. 11347026） and the Natural Science Foundation of Shan- dong Province （Grant Nos. ZR2016AM03 and ZR2017MA011）.
文摘Extending the recent work completed by Fan et al. [Front. Phys. 9（1）, 74 （2014）] to a two-mode case, we investigate how a two-mode squeezed vacuum evolves when it undergoes a two-mode amplitude dissipative channel, with the same decay rate ~, using the continuous-variable entangled state approach. Our analytical results show that the initial pure-squeezed vacuum state evolves into a definite mixed state with entanglement and squeezing, decaying over time as a result of amplitude decay. We also investigate the time evolutions of the photon number distribution, the Wigner function, and the optical tomogram in this channel. Our results indicate that the evolved photon number distribution is related to Jacobi polynomials, the Wigner function has a standard Gaussian distribution （corresponding to the vacuum） at long periods, losing its nonclassicality due to amplitude decay, and a larger squeezing leads to a longer decay time.
