论文标题
带相干性引起的对无泵的校正：在冷原子系统中可能的观察
Interband coherence induced correction to Thouless pumping: possible observation in cold-atom systems
论文作者
论文摘要
在无泵中，在绝热循环中，在一维绝缘子中的电荷传输是拓扑量化的。然而，对于非平衡初始状态，带相干性将引起先前未知的对泵的贡献。尽管本质上不是几何学，但这种贡献与泵浦协议的时间尺度无关。在这项工作中，我们对我们以前的发现[phys。 Rev. B 91，085420（2015）]在已经可用的冷原子设置中。我们表明，可以通过系统的哈密顿量的淬火获得带有带相干性的初始状态。然后在理论上和数字上检查后淬火系统中的绝热泵，其中显示器间相干性显示起重要作用，因此可以在实验中观察到。通过选择具有不同开关速度的绝热协议，我们还可以调整带相干性对绝热抽水的贡献。进一步提出的是，带相干性引起的对无泵的校正可能有助于捕获拓扑相变点。我们所有的结果都有直接的实验兴趣。
In Thouless pump, the charge transport in a one-dimensional insulator over an adiabatic cycle is topologically quantized. For nonequilibrium initial states, however, interband coherence will induce a previously unknown contribution to Thouless pumping. Though not geometric in nature, this contribution is independent of the time scale of the pumping protocol. In this work, we perform a detailed analysis of our previous finding [Phys. Rev. B 91, 085420 (2015)] in an already available cold-atom setup. We show that initial states with interband coherence can be obtained via a quench of the system's Hamiltonian. Adiabatic pumping in the post-quench system are then examined both theoretically and numerically, in which the interband coherence is shown to play an important role and can hence be observed experimentally. By choosing adiabatic protocols with different switching-on speeds, we also show that the contribution of interband coherence to adiabatic pumping can be tuned. It is further proposed that the interband coherence induced correction to Thouless pumping may be useful in capturing a topological phase transition point. All our results have direct experimental interests.
