论文标题
相位扩散和耗散性玻色 - 约瑟夫森连接处的波动
Phase diffusion and fluctuations in a dissipative Bose-Josephson junction
论文作者
论文摘要
我们分析了一维玻色 - 约瑟夫森连接（BJJ）的相扩散，量子波动及其光谱特征，该连接（BJJ）与骨热浴相连。我们显示了相扩散系数对现场相互作用参数$ u $的依赖性和零相和$π$ - 相模的温度。我们发现，在$π$ - 相模式下，只要$ u $低于临界值，而$ u $的函数的相位扩散协能降低了，而它却高于临界值。现场相互作用的这种临界性反映了约瑟夫森振荡与宏观量子自我捕获（MQST）方案之间的过渡。基于热规范的Wigner分布，我们计算了相干因子，以了解其对约瑟夫森振荡和MQST状态中温度和现场相互作用能量的依赖。此外，我们讨论了与相对相位的波动以及零和$π$相之间的相关光谱特性以及从弱耗散到强大耗散状态的群体失衡。
We analyze the phase diffusion, quantum fluctuations and their spectral features of an one-dimensional Bose-Josephson junction (BJJ) coupled to a bosonic heat bath. We show the dependence of the phase diffusion coefficient on the on-site interaction parameter $U$ and the temperature in zero-phase and $π$-phase modes. We find that in the $π$-phase mode, the phase diffusion co-efficient as a function of $U$ decreases so long as $U$ is below a critical value while it increases above the critical value. This criticality of on-site interaction reflects a transition between Josephson oscillation and macroscopic quantum self-trapping (MQST) regime. Based on the thermal canonical Wigner distribution, we calculate the coherence factor to understand its dependence on temperature and on-site interaction energy in Josephson oscillation and MQST regime. Furthermore, we discuss coherent and incoherent spectral properties in connection with the fluctuations of the relative phase and the population imbalance in both zero and $π$-phase modes from weak to strong dissipation regime.
