论文标题
具有参数非线性的Rabi模型中挤压的增强
Enhancement of squeezing in the Rabi model with parametric nonlinearity
论文作者
论文摘要
在相互作用的Qubit振荡器系统中，使用RABI模型中存在参数振荡器来研究挤压效果。基于广义旋转波近似，该近似在较宽的耦合强度和失调范围内很好地工作，将分析得出的近似能谱与哈密顿量的数值频谱进行了比较。对于两部分系统的初始状态，通过部分跟踪量子的自由度来获得与振荡器相对应的还原密度矩阵的动力学演化。振荡器的减小密度矩阵产生的非负相空间概率分布称为Husimi $ Q $ - 功能，该分布可用于计算正交方差。结果表明，在存在参数非线性项的情况下，可以大大增强RABI模型中产生的挤压。
The squeezing effect arises in the interacting qubit-oscillator system is studied with the presence of a parametric oscillator in the Rabi model. Based on the generalized rotating wave approximation which works well in the wide range of coupling strength as well as detuning, the analytically derived approximate energy spectrum is compared with the numerically determined spectrum of the Hamiltonian. For the initial state of the bipartite system, the dynamical evolution of the reduced density matrix corresponding to the oscillator is obtained by partial tracing over the qubit degree of freedom. The oscillator's reduced density matrix yields the nonnegative phase space quasi probability distribution known as Husimi $Q$-function which is utilized to compute the quadrature variance. It is shown that the squeezing produced in the Rabi model can be enhanced substantially in the presence of a parametric nonlinear term.
