The superposition of the eigenstates of the Nth powers(N≥3)of the annihilation operator of the non-harmonic oscillator is constructed.Its higher-order squeezing effect and antibunching effect are studied.The results show that the order of squeezing and antibunching effect are determined by the phase difference.
A method for construction of the k orthonormalized quantum eigenstates of the higher powers ak of the quantum-annihilation operator a is proposed, and their physical meaning is explored. Nonclassical properties of these quantum eigenstates are studied and the main results are as follows: (1) All of the eigenstates can be expressed as a linear superposition of k quantum-coherent states; (2) all of them are generalized quantum-coherent states; (3) for k\ensuremath{\ge}3, they have the Nth-order quantum squeezing for N=mk+k/2 (m=0,1,2, . . .) and even k, but no Nth-order quantum squeezing for other values of N and k; (4) for k\ensuremath{\ge}3, all of them exhibit the lowest- and higher-order quantum antibunching.
The antibunching properties for the eigenstates of the Kth powers (K≥3) of the annihilation operator of the q-deformed non-harmonic oscillator are investigated. The numerical method is used to study the properties influenced by the parameter q. The results show that the eigenstates exhibit antibunching effects in a number of intervals of x=β2, which reflects the intensity of the non-harmonic oscillator in q-deformation generalized coherent state. The effects are evidently influenced by the parameter q. When q is taken values departure from 1 greatly, these intervals become larger, and shift toward the positive x direction.
The superposition states, which are composed of the generalized q-coherent states of the non-harmonic oscillator, are presented. The quantum statistical properties of these states are studied. Then the influence of the superposition phase δ and the deformation parameter q on these nonclassical properties are discussed. It is shown that the superposition states exhibit higher-order (order of odd number) squeezing effect and antibunching effect respectively. When the superposition phase δ is taken values approach to 0 or π/2, these results approach the properties of the even or odd generalized q-coherent states of the non-harmonic oscillator. Especially, the effects are influenced by the parameter q. When the values of q is taken departure from 1 greatly, the nonclassical properties are more evidently.
The characteristics of the k th-power squeezing of a class of superposition states which involving two orthonormalized eigenstates of photon annihilation operator aN are studied.The result show that the characteristics of the k th-power squeezing of a class of superposition states which involving two orthonormalized eigenstates of photon annihilation operator aN are different from the characteristics of the k th-power squeezing of the orthonormalized eigenstates of photon annihilation operator aN clearly.No matter what N is an odd number or even number,the superposition states own amplitude k(k=Nt or Nt/2) th-power squeezing,but for the orthonormalized eigenstates of aN,only when N is even number there exist amplitude k(k=(2P+1)N/2) th-power squeezing.Owing to that,when phase difference δ=2mπ/t(m is integer),the superposition states don′t own amplitude k th-power squeezing;when δ=π,only N and t are odd number simultaneously,the superposition states may own amplitude k th-power squeezing;when δ=π/2,t≠4m,the superposition states own amplitude k th-power squeezing;thus the phase difference of parameter has key effect on amplitude k th-power squeezing.
We introduce a quantum antibunching effect. The quantum antibunching effect of the K eigenstates of the K th powere ( K greater than or equal to 3) of the annihilation operator in the Q-deformed non-harmonic oscillator is investigated. The physical meaning of the K states are explored. The results show that there is the quantum antibunching effect in all of those states. All of them can be generated by a linear superposition of generalized coherent states produced by the time-dependent Q-deformation non-harmonic oscillator at different instants.