Topology, interactions, and disorder in neutral-atom quantum simulators

Topological phases of matter exhibit striking properties such as robust edge transport and quantized responses, yet understanding their interplay with interactions and disorder remains a central challenge in modern condensed matter physics. Analog quantum simulators based on neutral atoms now provide a powerful platform to explore these phenomena with single-particle resolution and control. Floquet engineering has emerged as a versatile approach for realizing topological phases of matter, though most experiments so far have been limited to non-interacting systems.

Here, I will present recent experiments where we realized a low-temperature, strongly interacting Mott–Meissner phase in large-scale bosonic flux ladders, revealing the characteristic scaling of chiral edge currents with interaction strength. The topological properties of Floquet systems, however, transcend those of their static counterparts. We developed an experimental technique that directly reveals these anomalous regimes by imaging and manipulating topological edge modes in periodically driven honeycomb lattices. This approach paves the way toward studying topological phase transitions in the presence of disorder, where conventional observables fail because they rely on translational invariance. Using mode matching between a localized Bose-Einstein condensate and the edge mode, we observe disorder-driven transitions between distinct Floquet topological phases and explore their robustness in the large-disorder regime.

Together, these results establish neutral-atom quantum simulators as a powerful platform for exploring the rich interplay of topology, interactions, and disorder - and for uncovering genuinely out-of-equilibrium topological phases of matter, such as anomalous Floquet Anderson insulators, where a fully localized bulk coexists with extended, topologically protected edge modes.