论文标题
在Bose-Hubbard模型中杂质
Impurity dephasing in a Bose-Hubbard model
论文作者
论文摘要
我们从开放的量子系统的角度研究了在零温度下以零温度嵌入的二级杂质的动力学。给出了整个相图的分解结果，介绍了接近超氟和莫特绝缘子之间过渡的关键区域。特别是，我们展示了马尔可夫行为的变质和偏差是如何敏感的，是否在相称的或不一致的密度下跨越过渡。强调了Bose-Hubbard环境及其非高斯统计数据的作用，超出了标准的独立玻色子模型。我们对最近开发的方法的分析方法[Phys。 Rev. Research 2，033276（2020）] - 与奴隶玻色子方法密切相关 - 使我们能够捕获整个相图上的相关性。这种半分析方法使我们深入了解了超氟和莫特相中自旋脱碳的物理学以及接近相变。
We study the dynamics of a two-level impurity embedded in a two-dimensional Bose-Hubbard model at zero temperature from an open quantum system perspective. Results for the decoherence across the whole phase diagram are presented, with a focus on the critical region close to the transition between superfluid and Mott insulator. In particular, we show how the decoherence and the deviation from a Markovian behaviour are sensitive to whether the transition is crossed at commensurate or incommensurate densities. The role of the spectrum of the Bose-Hubbard environment and its non-Gaussian statistics, beyond the standard independent boson model, is highlighted. Our analysis resorts on a recently developed method [Phys. Rev. Research 2, 033276 (2020)] - closely related to slave boson approaches - that enables us to capture the correlations across the whole phase diagram. This semi-analytical method provides us with a deep insight into the physics of the spin decoherence in the superfluid and Mott phases as well as close to the phase transitions.
