Quantum gas microscopes have opened new windows on strongly correlated quantum matter, providing access to microscopic observables, entanglement properties, and out-of-equilibrium dynamics that are inaccessible to conventional probes. In this colloquium, I will discuss two complementary directions we are pursuing in our laboratories in Munich.
In our fermionic quantum gas microscope, simultaneous single-particle-resolved detection of spin and charge allows us to probe the doped Fermi-Hubbard model at low temperatures, a regime inaccessible to unbiased classical numerical methods. I will present our latest results on the pseudogap phase, including higher-order spin-charge correlations, entanglement signatures within the pseudogap, and evidence for incipient stripe formation at low temperatures. Comparison with state-of-the-art numerical methods lets us test these methods and sharpen the picture of how the magnetic and charge degrees of freedom intertwine as the system is doped.
In a second series of experiments, we realize non-equilibrium quantum simulation of lattice gauge theories with a new cesium quantum gas microscope. Using a square optical superlattice, we realize a two-dimensional U(1) lattice gauge theory on more than 3,000 sites and dynamically prepare extended regions of a U(1) quantum spin liquid of Rokhsar-Kivelson type. A new doublon-resolved detection method allows us to verify Gauss’s law directly, and we observe real-space correlations together with characteristic momentum-space pinch points. Using round-trip interferometric protocols, we obtain direct evidence for coherence between many-body configurations over ~100 lattice sites, establishing non-equilibrium protocols as a route to highly entangled states beyond thermal equilibrium.