A messy topological wire Adding irregularity to a system can lead to a transition from a more orderly to a less orderly phase. Meier et al. demonstrated a counterintuitive transition in the opposite direction: Controlled fluctuations in the system's parameters caused it to become topologically nontrivial. The starting point was a one-dimensional lattice of ultracold rubidium atoms in momentum space whose band structure was topologically trivial. The researchers then introduced fluctuations in the tunneling between the lattice sites and monitored the atomic “wires” as the amplitude of the fluctuations increased. The wires first became topologically nontrivial and then went back to trivial for sufficient disorder strengths. Science, this issue p. 929 Controlled fluctuations in the tunneling between the sites of an atomic wire in momentum space cause a topological transition. Topology and disorder have a rich combined influence on quantum transport. To probe their interplay, we synthesized one-dimensional chiral symmetric wires with controllable disorder via spectroscopic Hamiltonian engineering, based on the laser-driven coupling of discrete momentum states of ultracold atoms. Measuring the bulk evolution of a topological indicator after a sudden quench, we observed the topological Anderson insulator phase, in which added disorder drives the band structure of a wire from topologically trivial to nontrivial. In addition, we observed the robustness of topologically nontrivial wires to weak disorder and measured the transition to a trivial phase in the presence of strong disorder. Atomic interactions in this quantum simulation platform may enable realizations of strongly interacting topological fluids.

中文翻译：

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无序原子线中拓扑安德森绝缘体的观察

凌乱的拓扑线 向系统添加不规则性会导致从更有序的阶段过渡到不太有序的阶段。迈尔等人。证明了相反方向的违反直觉的转变：系统参数的受控波动导致它在拓扑上变得不重要。起点是动量空间中超冷铷原子的一维晶格，其能带结构在拓扑上是微不足道的。然后，研究人员在晶格位点之间的隧道中引入波动，并随着波动幅度的增加监测原子“线”。电线首先在拓扑上变得不平凡，然后又回到平凡以获得足够的无序强度。科学，这个问题 p。929 动量空间中原子线位置之间隧道的受控波动导致拓扑转变。拓扑和无序对量子传输有着丰富的综合影响。为了探究它们的相互作用，我们基于超冷原子离散动量态的激光驱动耦合，通过光谱哈密顿工程合成了具有可控无序的一维手性对称线。测量突然猝灭后拓扑指示剂的整体演化，我们观察到拓扑安德森绝缘体相，其中增加的无序将导线的能带结构从拓扑微不足道驱动到非微不足道。此外，我们观察到拓扑非平凡线对弱无序的鲁棒性，并测量了在存在强无序的情况下向平凡相的转变。