论文标题
在强耦合自旋振荡系统中对自旋小猫状态的研究
Study of the spin kitten states in a strongly coupled spin-oscillator system
论文作者
论文摘要
使用绝热近似方法,在强和超肌耦合方案中,明确研究了双方QUDIT振荡器Hamiltonian的低自旋值。引入了混合分解相空间上的准蛋白酶密度。在复合相空间的一个扇区集成,恢复了互补子系统的准整体性分布。在强耦合方案中,Qudit熵显示了准二元折叠和复兴的模式,其中局部最小的非零构型出现在复兴时间的合理分数上,对应于旋转小猫状态。从双分化的初始状态开始,通过对角线旋转PQ代理显示了非经典临时自旋小猫状态的演变。通过构建旋转断层图,采用正定概率分布,在任意旋转的框架中体现了相应密度矩阵的对角线元件,从而进一步证实了瞬态自旋小猫状态的形成。作为非经典性的另一种表现,观察到双方进化过程中自旋挤压状态的出现。在Ultrastrong耦合域中,产生了大量相互作用的依赖模式及其谐波。随之而来的阶段随机化消除了系统的准静脉,这现在被驱动到熵的稳定下,并伴随其稳定值周围有随机波动。在光发射事件的强和超晶体耦合领域中,尤其是针对小旋转值的抗爆发事件。
Utilizing an adiabatic approximation method a bipartite qudit-oscillator Hamiltonian is explicitly studied for low spin values in both strong and ultrastrong coupling regimes. The quasiprobability densities on the hybrid factorized phase space are introduced. Integrating over a sector of the composite phase space, the quasiprobability distributions of the complementary subsystem are recovered. In the strong coupling regime the qudit entropy displays a pattern of quasiperiodic collapses and revivals, where the locally minimum nonzero configurations appearing at rational fractions of the revival time correspond to the spin kitten states. Starting with a bipartite factorizable initial state the evolution to the nonclassical transitory spin kitten states are displayed via the diagonal spin PQ-representation. The formation of transient spin kitten states is further substantiated by constructing the spin tomogram that employs the positive definite probability distributions embodying the diagonal elements of the corresponding density matrix in an arbitrarily rotated frame. As another manifestation of nonclassicality the emergence of the spin squeezed states during the bipartite evolution is observed. In the ultrastrong coupling domain a large number of interaction dependent modes and their harmonics are generated. The consequent randomization of the phases eliminates the quasiperiodicity of the system which is now driven towards a stabilization of the entropy accompanied with stochastic fluctuations around its stabilized value. Both in the strong and ultrastrong coupling realms antibunching of the photoemission events are realized particularly for the small spin values.