In this thesis, we studied the effects of the initial field state and thermal environment on quantum nonlocality and purity in atom-field system, in which the field initially in the squeezed vacuum state and in the squeezed coherent state are considered respectively 本文研究了光场初态和热库性质对原子?场耦合系统量子非局域性的影响,分别讨论了腔场初始处于压缩真空态和压缩相干态两种情形。
On the one hand, we deduce the off-diagonal term of reduced density matrix is inner-product of two coherent states and we carry out decoherence in macroscopic limits in two special case, on the other hand, we delay decoherent time by controlling the interaction coefficient . in other part, we define two kind independent phase operators by improving two-mode squeezing coherent states in two-mode phase space and resolve their eigenstates 在第二部分中,我们在双模相位空间里利用双模压缩相干态所对应的算符定义二类独立的相位算符并相应求出本征态,而它的产生算符和湮灭算符是通过简谐振子的产生算符和湮灭算符经过正则变换得到的。