SU（1,1）相干态的波函数

朱燕娟, 沈德元

本文研究SU(1.1)压缩相干态在简并参量放大和非简谐振子这两种非线性介质模型中的演化规律。研究结果表明:在简并参量放大中,SU(1.1)压缩相干态保持并增强压缩效应;在非简谐振子模型中,它的压缩效应随时间变化而迅速消失,在这两种非线性光学介质模型中.SU(1.1)压缩相干态保持光子聚束效应。

Constança Providência, João da Providência, Y. Tsue +1 more

The two-level pairing model obeying the su(2) ⊗ su(2)-algebra, which was discussed in a previous paper, is re-formed in the framework of the su(1,1) ⊗ su(1,1)-algebra in the Schwinger boson representation. With the aid of the MYT mapping method, the Schwinger boson representation is reduced to the Holstein-Primakoff boson representation, which is expressed in terms of two kinds of bosons. Further, with the aid of the squeezed coherent state, the classical counterpart is obtained.

陈志高, 杨亚天

姜迅东, 曾谨言

Y. Tsue, Constança Providência, João da Providência +1 more

Standing on the results for the minimum weight states obtained in the previous paper (I), an idea how to construct the linearly independent basis is proposed for the su(n)-Lipkin model. This idea starts in setting up m independent su(2)-subalgebras in the cases with n=2m and n=2m+1 (m=2,3,4,...). The original representation is re-formed in terms of the spherical tensors for the su(n)-generators built under the su(2)-subalgebras. Through this re-formation, the su(m)-subalgebra can be found. For constructing the linearly independent basis, not only the su(2)-algebras but also the su(m)-subalgebra play a central role. Some concrete results in the cases with n=2, 3, 4 and 5 are presented.

Xiao-Guang Wang, Barry C. Sanders, Shaohua Pan

Entangled SU (2) and SU (1,1) coherent states are developed as superpositions of multiparticle SU (2) and SU (1,1) coherent states. As a special example of entangled SU (2) coherent states, entangled binomial states are introduced and these entangled binomial states enable the contraction from entangled SU (2) coherent states to entangled harmonic oscillator coherent states. Entangled SU (2) coherent states are discussed in the context of pairs of qubits. We also introduce the entangled negative binomial states and entangled squeezed states as examples of entangled SU (1,1) coherent states. A method for generating the entangled SU (2) and SU (1,1) coherent states is discussed and degrees of entanglement calculated. Two types of SU (1,1) coherent states are discussed in each case: Perelomov coherent states and Barut-Girardello coherent states.