Engineered Strongly-Interacting Lattice Models with Atomic Quantum Simulators

Quantum gas microscopes probe quantum many-body lattice states via projective measurements in the occupation basis, enabling access to various density and spin correlations. Phase information, however, cannot be directly obtained in these setups. Here we introduce a phase microscope for quantum gases, which measures the local phase profiles with single lattice-site resolution [1], based on Fourier-space manipulation in a matter-wave microscope [2]. We use the phase microscope to study the coherence properties of an ultracold Bose gas in a two-dimensional optical lattice across the thermal phase transition. Furthermore, we discuss protocols for many-body phase microscope, which will give access to various long-range off-diagonal correlators in experimentally realistic settings, which are highly relevant for characterizing many-body phases such as d-wave superconductors or fractional Chern insulators [3]. [1] Brüggenjürgen et al., arXiv:2410.10611 (2024) [2] Asteria et al., Nature 599, 571-575 (2021) [3] Weitenberg et al., arXiv:2602.12142 (2026)

In the vicinity of a continuous phase transition, correlations can grow across all length scales, as reflected in the divergence of the correlation length. In a finite size system, however, this growth is limited by the system size, preventing correlations from extending beyond the system boundaries. This constraint leads to the emergence of a non-Gaussian regime, in which the statistics of the order parameter become universal and non-Gaussian. In this talk, I will present our latest observation of universal non-Gaussian order-parameter statistics across the interaction-induced superfluid–normal phase transition using ultracold bosons loaded into an optical lattice.

Unraveling the microscopic physics underlying doped Hubbard models constitutes a central goal of modern quantum simulation approaches. The ability of such platforms to perform quantum projective measurements of strongly correlated quantum matter, with full spin and charge resolution, has already led to the discovery of hidden antiferromagnetism in the dimensional Hubbard models. In this talk we introduce the concept of "hidden order” as a new paradigm for constructing non-Ginzburg Landau phases of matter: it connects seemingly disjoint concepts, including spontaneous symmetry breaking, symmetry-protected topological order and error correction. We apply these ideas to generalize hidden antiferromagnetism from one dimensional chains to two-dimensional doped Hubbard models. This leads us to propose a theory of the pseudogap phase as a Higgs-phase of an emergent Ising gauge theory. Our predictions will help guide future quantum simulation experiments: from the exploration of high-temperature superconductivity to the search for novel states of quantum matter.

The exploration of superfluidity has fascinated physicists for decades, spanning an extraordinary variety of systems—from solids and liquids to dilute gases and even light. At its core, superfluidity arises when many bosonic quantum particles interact collectively, giving rise to macroscopic quantum coherence. Traditionally, these interactions have been assumed to be short-ranged, isotropic, and contact-like, providing the simplest and most widely studied framework for the emergence of superfluid behavior. But what happens when more complex interactions are allowed to enter the game? What if interactions acquire directionality, extend over longer distances, or compete with one another? Under such conditions, remarkably rich phenomena emerge. Spatially homogeneous systems may spontaneously develop density modulations, forming stripes or periodic structures. This conceptual shift immediately raises a cascade of fundamental questions: What does superfluidity mean in the presence of broken translational symmetry? Can the intrinsic localization of a periodic structure coexist with the frictionless flow of a superfluid? Could a solid, with its crystalline rigidity, exhibit superfluid behavior—or could a superfluid itself acquire crystalline order? These long-standing questions have recently found compelling answers with the experimental discovery of supersolid quantum states—exotic phases of matter that simultaneously display superfluid coherence and crystalline density order. In this colloquium, I will present the experimental realization of supersolidity in magnetic quantum gases, focusing on results obtained in Innsbruck. I will introduce the key physical ingredients step by step: the softening of roton excitations as a precursor to the supersolid phase transition, the dynamical emergence of broken symmetries, and the observation of quantized vortices in rotating supersolid states. Together, these results establish supersolidity as a robust and controllable platform for exploring the interplay between order, coherence, and collective quantum dynamics.

Ultracold dipolar molecules offer access to strong long-range interactions and have been envisioned as a powerful platform for many-body quantum physics. However, cooling molecules to quantum degeneracy has remained a long-standing challenge. Recently, we have created the first BEC of dipolar molecules [1]. We evaporatively cool a gas of sodium-cesium molecules to below 10 nanokelvin, deep in the quantum degenerate regime, with lifetimes of several seconds. This dramatic improvement over previous molecular cooling efforts is enabled by collisional shielding via microwave dressing, suppressing inelastic losses by four orders of magnitude [2]. Microwave dressing also provides an exceptional level of tunability of dipole-dipole interactions, opening the door to novel phases of matter in molecular quantum liquids. Most recently, we have observed self-bound droplets in a gas of strongly dipolar molecules [3]. In this talk, I will describe our experimental approach, discuss recent results, and give an outlook on new opportunities enabled by molecular BECs for quantum simulation and many-body quantum physics. In addition, I will briefly highlight our broader efforts in quantum, including recent advances on single-atom trapping in metasurface optical tweezer arrays [4]. [1] Bigagli, Yuan, Zhang, et al., Observation of Bose-Einstein condensation of dipolar molecules, Nature 631, 289-293 (2024) [2] Yuan, Zhang, et al., Extreme loss suppression and wide tunability of dipolar interactions in an ultracold molecular gas, arXiv:2505.08773 (2025) [3] Zhang, Yuan, et al., Observation of self-bound droplets of ultracold dipolar molecules, arXiv:2507.15208 (2025) (Nature, in print) [4] Holman, Xu, et al., Trapping of single atoms in metasurface optical tweezer arrays, Nature, 649, 859-865 (2026

In this talk I will discuss the realization of a programmable quantum simulator of non-equilibrium many-body dynamics using a two-dimensional crystal of approximately 100 trapped ions that implements the Dicke model of collective light–matter interactions. We use optical spin-dependent forces to couple the ions’ internal states to a shared vibrational mode, enabling fully unitary dynamics beyond mean-field and few-body limits and allowing controlled tuning between integrable and strongly interacting regimes. In the near-integrable limit, we observe coherent collective behavior, including a dynamical phase transition between ferromagnetic and paramagnetic spin order. As the spin–phonon coupling is increased, the dynamics become non-integrable and exhibit clear signatures of chaos, with irregular phase-space trajectories and rapid growth of excitations and entanglement, quantified by the Reyni entropy. Quenches from unstable points generate correlated spin–phonon pairs which we inferred generate two-mode squeezing up to 2.6 dB below the standard quantum limit, followed by manybody collapses and revivals. These results establish large ion crystals as scalable analog quantum simulators of non-equilibrium light–matter physics and provide a controlled platform for studying entanglement growth, information scrambling, and quantum chaos in closed quantum systems.

I will present the observation of density-wave ordering in strongly interacting Fermi gases induced by long-range cavity-mediated interactions. By dynamically increasing the strength of these interactions, high-resolution in situ imaging reveals the formation of density waves, accompanied by a macroscopic population of photons in the cavity mode. Crucially, both the photonic and atomic signals are measured along the same quantum trajectory in a single shot, enabling a direct observation of the correlations between the intracavity field and the emergent spatial ordering of atoms. These correlations persist despite significant fluctuations originating from the initial seeding of the instability. Our results demonstrate that combining high-resolution imaging with cavity QED opens new avenues for engineered atomic ensembles, including tailored trapping potentials and local addressing of atomic ensembles.

Holographic field theories represent a phase of matter that is dual to bulk gravity and that provides paradigms for non-Fermi-liquid behavior and for extreme quantum chaos, making it relevant for communities from quantum gravity, quantum information, and condensed matter. Quantum simulators based on ultracold atoms and similar platforms with pristine microscopic control offer the exciting prospect to probe its properties from first principles and in the presence of strong quantum fluctuations. However, it remains an exceedingly hard challenge to realize such holographic matter in quantum simulator laboratory experiments. In this talk, I will give an overview of exotic properties of holographic matter, including its large quantum chaoticity and its strong complexity in terms of quantum-information resources, focusing on the paradigmatic Sachdev-Ye-Kitaev (SYK) model, a model of fermions with disordered all-to-all interactions, as well as an extension dubbed Yukawa-SYK where the interactions between fermions are mediated by bosons. I will also highlight recent theoretical and experimental progress of how such models could be realized in setups of ultracold fermionic atoms in an optical cavity. With this, I aim to illustrate the extreme richness of physics encountered in the quantum simulation of holographic matter.

Designing the amplitude and range of couplings in quantum systems is a fundamental tool for exploring a large variety of quantum mechanical effects. In this talk, we consider off-resonant photon scattering processes on a geometrically shaped molecular cloud. Our analysis shows that such a setup is properly modeled by a Bose-Hubbard Hamiltonian where the range, amplitude and sign of the tunneling processes of the scattered photonic modes can be accurately tuned. Specifically, by varying the molecular distribution, we demonstrate that different configurations characterized by geometrical frustration, long-range power law hopping processes, and non-local gauge fields can be achieved. These results thus represent a powerful and alternative approach to perform an accurate Hamiltonian engineering of quantum systems with non trivial coupling structures.

Ultracold polar molecules are emerging as a powerful platform for quantum simulation, quantum computing, and cold chemistry. In this talk, I will first review the challenges and status of cooling a Fermi gas of polar molecules in order to realize and explore exotic quantum phases such as p-wave superfluids and Bose-Einstein condensates of dipolar tetramers. Then I will show our observation of controlled symmetry breaking of the Fermi surface in a deeply degenerate Fermi gas of polar molecules, a direct quantum many-body signal of dipolar interactions of fermionic molecules. In the end, I will show our progress of developing a compact dual-species setup for producing lithium-rubidium molecules.

Production of low-entropy samples of ultracold dipolar molecules would enable observations of novel phases and dynamics predicted by spin-motion models [1, 2], such as the generalized t-J model [3]. Here, we report evaporative cooling of ultracold KRb molecules confined in either 3D or 2D trap geometries into deep Fermi degeneracy. Efficient evaporation is initiated by providing a favorable ratio of elastic to inelastic dipolar collisions, enabled by resonant electric field shielding for 3D samples [4, 5] or by purely repulsive dipolar interactions for quasi-2D samples [6] in both bilayer and monolayer configurations. We observed that the evaporation efficiency into deep degeneracy is limited by the onset of Pauli blocking that suppresses the ratio of elastic to inelastic collisions. This work explores the influence of dimensional confinement on the interplay of the density of states of degenerate fermions and dipolar scattering, setting the stage for future studies of novel many-body dynamics with deeply degenerate polar molecules. [1] J. Li, et al, Nature 614, 70–74 (2023) [2] C. Miller, et al., Nature 633, 332–337 (2024) [3] A. N. Carroll, et al., Science 388, 381-386 (2025) [4] K. Matsuda, et al., Science 370, 1324-1327 (2020) [5] J. Li, et al, Nat. Phys. 17, 1144–1148 (2021) [6] G. Valtolina, et al., Nature 588, 239–243 (2020)

What happens when quantum simulations become cold enough to surprise us? So far, quantum simulations have primarily served as impressive proof-of-principle demonstrations, realizing a wide range of many-body quantum phases. However, temperatures have remained too high to truly access uncharted regimes relevant to strongly correlated quantum materials. In this talk, I will present a recent breakthrough in which we use an ultracold-atom realization of the Fermi–Hubbard model to explore pseudogap physics in the doped regime. By achieving a several-fold reduction in temperature, we enter a new regime and observe, unexpectedly, a pronounced peak in the compressibility near 1/8 doping. This feature appears to separate a conventional metallic phase from a pseudogap phase. Furthermore, we measure characteristic signatures of a pseudogap in the excitation spectrum and begin to observe the emergence of spin stripe correlations. This work represents a key advance in quantum simulation: it demonstrates that we can now address central open questions in condensed matter physics using controlled experiments in regimes that lie at the frontier of classical numerical methods.

The pairing of charge carriers in repulsively interacting quantum system is a key step in the quest to understand unconventional superconductivity in quantum materials. In this talk, I will discuss our new insights into different types of charge carriers, how Hamiltonian parameters like further range interactions or hopping (t') can be used to tune between them, and what conclusions we can make for the finite doping regime.

Local Hilbert spaces with large dimension are of key interest for quantum information with applications in quantum computing and memories, quantum simulations and metrology. Thanks to its weak coupling to external perturbations, the large ground-state nuclear spin manifold of fermionic alkaline-earth atoms is an exciting resource to explore for quantum information. Simultaneous single atom and state-resolved detection however remains an outstanding challenge limiting the development of novel quantum computing and simulation schemes beyond qubits. Here, we report on a new imaging technique enabling the simultaneous detection of up to four quantum states encoded in the nuclear spin manifold of a single fermionic strontium atom within 100 microseconds, with state-resolved detection fidelities ranging from 0.936 to 0.997. This technique is further used to track the highly coherent nuclear spin dynamics after a quench highlighting the potential of this system for quantum information. These results offer fascinating perspectives for quantum science with multi-electron atoms ranging from qudit-based quantum computing to quantum simulations of the SU(N) Fermi-Hubbard model.

The anyon Hubbard model has recently been investigated experimentally both by the Greiner group in Harvard in a driven optical lattice and by the Nägerl group in Innsbruck by means of impurities. It can be represented by a bosonic tight-binding chain with number-dependent Peierls phases. I will given an introduction to the model and argue that it describes non-trivial particle exchange in one spatial dimension, associated with non-trivial Berry phases around Fock-space loops. Moreover, I will discuss two- and three-body bound states in and out of the continuum in that model. Finally, a recently proposed lattice model for so-called traid anyons will be introduced. It captures non-trivial three-particle braiding.

Transport properties are central to the characterization of quantum matter, yet measuring them typically requires probing the response to an external drive. Following Kubo's theory, transport coefficients are expressed through unequal-time current-current correlators, making direct access from static ground-state properties highly challenging. In this talk, I will present a scheme to extract topological transport coefficients by directly measuring local static ground-state currents, quantities readily accessible in quantum-engineered platforms. Exploiting the exponential decay of correlations in gapped systems, I will show that the local Hall response of correlated insulators can be reconstructed from a small set of quasi-local current observables, yielding explicit relations to a practical local Chern marker capable of identifying topologically ordered phases at the level of individual lattice sites. I will further introduce a scalable digital protocol for measuring the required generalized currents in quantum simulators.

Quantum simulation is entering a regime where microscopic control can be used not only to reproduce model Hamiltonians, but also to engineer entirely new forms of quantum matter. In this talk I will present a series of recent experiments illustrating this perspective, using ultracold atoms and molecules as complementary quantum simulation platforms. I will first discuss strongly interacting one-dimensional Bose gases, where controlled driving enables the preparation of highly excited many-body states with unusual statistical properties, including fractional Fermi seas. These systems provide a unique laboratory for exploring emergent quasiparticles, generalized quantum statistics, and non-equilibrium many-body dynamics. I will then present recent results on many-body dynamical localization, demonstrating how periodic driving and interactions can give rise to robust non-ergodic behaviour in the absence of disorder. In the second part of the talk, I will turn to ultracold KCs molecules, where long-range dipolar interactions considerably expand the range of many-body Hamiltonians accessible to experiments. Finally, I will discuss ongoing efforts toward realizing interacting topological lattice models in one dimension using spin-dependent optical lattices, illustrating how synthetic geometry can become an additional design tool for quantum matter. Together, these examples highlight a broader research direction in which interactions, driving, dimensionality and internal degrees of freedom are engineered to realize emergent many-body phenomena beyond conventional equilibrium phases.

Ultracold atoms in optical lattices have been established as a powerful toolbox for quantum optics, enabling the study of many-body physics and the simulation of strongly correlated condensed matter systems. Over the past two decades, a new window on the physics of these systems has been opened by the experimental realization of quantum gas microscopes, which allow single-site imaging and addressing of the atoms. Until recently, quantum gas microscopes had been realized with atomic species with a negligible magnetic moment, which interact only via short-range contact interaction. Here, we report on the progress towards a quantum gas microscope for dysprosium. With this new setup, we aim to probe extended Bose-Hubbard and extended Fermi-Hubbard models and observe novel and exotic magnetic phases in the strongly dipolar regime.

Experiments on dipolar quantum systems (magnetic atoms, polar molecules, Rydberg atoms) are opening interesting possibilities for the quantum simulation of spin models of interest in quantum magnetism. In particular, dipoles in triangular ladders (made with optical lattices or tweezer arrays) may allow for the interplay between frustration and long-range interactions, allowing for the realization of intriguing phases and phase-transitions, such as a dipole-induced transition between a chiral-superfluid and a non-chiral two-component superfluid, or the realization of chiral and nematic spin phases [1]. Interestingly, dipolar bosons in triangular ladders may realize an intriguing state, the so-called anyon condensate [2]. I will comment on what is meant here with anyons, and discuss first results that show that properly-tuned dipoles can be employed to realize this peculiar state [3]. [1] A. Dasgupta, M.Lacki, H. Korbmacher, G. A. Dominguez-Castro, J. Zakrzewski, and Luis Santos, PRA 113, L031301 (2026) [2] C. D. Batista, and R. D. Somma, Phys. Rev. Lett. 109, 227203 (2012). [3] A. Dasgupta and L. Santos, on-going.

Ultracold molecules are an emerging platform for quantum science that combines the techniques of atomic physics pioneered over the last half century, including quantum-state control and single particle detection/manipulation, with molecules' inherently rich internal structure. I will present new efforts at UChicago toward building novel quantum phases of matter using the emerging technology of highly polar molecules cooled to nanokelvin temperatures. Specifically, we hope to realize exotic topological superfluids built from interacting gases of KAg molecules, which could feature extraordinary characteristics such as resistance to disorder, frictionless flow, and the emergence of Majorana particles. Another complementary goal is to leverage the strong dipole-dipole interactions to pioneer novel ways to load molecules into large-scale, defect-free, low-entropy arrays.

We will report on theoretical models describing the onset and decay of metastable spatial patterns of quantum gases of bosons in high-finesse cavities. The theoretical predictions are compared with experimental measurements performed in the group of Tobias Donner at ETH in Zürich. We show that our theory provides a powerful framework for the description of cavity-induced dynamics of quantum matter. In doing so, it permits to connect models of statistical mechanics with cavity-QED experimental platforms, thus enabling quantum simulation of long-range interacting matter.

We study equilibrium spin diffusion in a square-lattice quantum S=1/2 XY-model both experimentally and theoretically. We employ a hard-core boson quantum simulator in a large optical lattice and a recently developed dynamic high temperature expansion method, respectively. For the first time our study achieves a match between the theoretical and experimental spin diffusion constant and maps out its significant temperature dependence. These results represent important progress in the validation of state-of-the-art quantum simulation.

Realizing strongly correlated topological phases of ultracold gases is a central goal for quantum gas experiments. Due to the difficulty in preparing these phases, ongoing experiments are focusing on ensembles of few atoms, and the preparation of a fractional quantum Hall state of two bosonic atoms has been achieved. Beyond their preparation, the characterization of these few-body states poses a unique challenge due to their small system size. I will discuss which signatures can be used, and show that hallmark fingerprints of fractional quantum Hall phases, such as a quantized Hall conductivity, or chiral edge modes, can be extracted in few-particle systems through local density measurements.

Interactions can play a determinant role in low dimensions for topological and chiral states of matter by giving rise to interesting emergent phenomena such as quasiparticle fractionalization and quantum phase transitions. Recent experimental evidence from Floquet engineered ultracold atomic systems, have provided a starting point for observing correlated vortex structures of the Laughlin bosonic Hall effect. Motivated by these experimental advances, we have investigated the quantum dynamics of large vortices in strongly interacting superfluids. For one quantum of flux and close to half-filling, the change in sign of the Hall conductivity suggests an abrupt change in vortex response and dynamics, due to effective strong quantum fluctuations. In this contribution we will present some preliminary results on vortex dynamics in the presence of strong correlations for different filling factors, giving rise to chiral vortex motion and non-trivial trajectories near to half-filling. We provide a mapping to a dual effective free theory explaining our observations. These results motivate novel transport measurements to delve into the phenomenology of single and multi-vortex dynamics in state-of-the-art bosonic platforms.

I will present the results of recent experiments performed with multicomponent 173Yb fermions in optical lattices, in the presence of strong atom-atom interactions and coherent driving between internal states. I will discuss the realization of multi-component Fermi-Hubbard systems, where a coherent laser coupling between different states can lead to flavour-selective Mott localization [1]. I will also discuss recent experiments where we have measured Hall transport in interacting fermionic ladders, where the laser coupling implements the action of a strong background magnetic field on effectively charged particles: I will show a strong dependence of the Hall response upon changing atom-atom interactions [2] and discuss the direct measurement of Hall voltages and resistances, which provide a direct connection between cold-atom simulators and the measurement of electric quantities in solid-state systems [3]. Finally, I will present the realization of new experimental platforms with programmable Rydberg arrays of individually trapped two-electron Yb and Sr atoms, both for analog quantum simulation of many-body quantum dynamics, and for the investigation of new approaches to atom-based quantum computing. [1] D. Tusi et al., Nat. Phys. 18, 1201 (2022). [2] T. Zhou et al., Science 381, 427 (2023). [3] T. Zhou et al., Nat. Comm. 16, 10247 (2025).

The deterministic preparation of strongly correlated quantum states is a key challenge of quantum simulation Reaching these states is of particular interest in fermionic systems, where the combination of Pauli exclusion, strong interactions, and entanglement gives rise to phenomena such as unconventional superconductivity, frustrated magnetism, and topological order. State preparation in a quantum simulator typically relies on one of two complementary approaches. The first is the analog approach, where correlations develop through Hamiltonian evolution either from a thermal ensemble or from an uncorrelated product state. The second is the digital approach, where correlations are built using gate sequences. In the analog method, the physics of the target Hamiltonian naturally emerges through adiabatic evolution, which is, however, limited by finite temperature and closing energy gaps. While digital methods offer programmable control, they demand a high level of connectivity and coherence for the simulation of fermionic systems, which current platforms lack. In our work [3], we build strongly correlated quantum states by combining analog methods of bulk Hamiltonian evolution with programmable digital gate sequences based on entangling atomic collisions [1] and geometric gates [2]. Using analog state preparation as a first step, we isolate four-fermion chains as fundamental building blocks and apply programmable gate-based circuits to encode their correlation structure. With this method we are able to prepare quantum correlations that are not native to the underlying Hamiltonian. This includes states with non-local configurations, which we can verify using coherent rearrangement and local two-body readout. Our resulst establish an efficient and scalable approach to the preparation, manipulation and measurement of strongly correlated many-body states of fermions.

Since its first realization in the early 2000s, quantum simulation of Hubbard models with ultracold atoms has largely relied on a top-down approach, wherein a dilute gas is evaporatively cooled to degeneracy before being loaded into the optical lattice of interest. In this talk, I will discuss our recent work realizing a new bottom-up approach to Hubbard simulation with assembled strontium-86 atoms in a hybrid tweezer-lattice architecture. Our protocol utilizes atomic rearrangement via optical tweezers and ground-state sideband cooling to initialize Fock states in a deep lattice as the starting resource. By appropriately manipulating optical potentials, we adiabatically connect this assembled Fock state to a Bose-Hubbard superfluid. We characterize the in-situ and time-of-flight density distributions of the resulting state, comparing the former to finite-temperature quantum Monte Carlo to establish the presence of a significant superfluid fraction. Our results pave the way for further explorations of many-body itinerant systems using atomic assembly.

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Quantum simulation provides a powerful route for exploring many-body phenomena beyond the capabilities of classical computation. Existing approaches typically proceed in the forward direction: a model Hamiltonian is specified, implemented on a programmable quantum platform, and its phase diagram and properties are explored. In this talk, I will present a quantum algorithmic framework for inverse quantum simulation, enabling quantum material design with desired properties. Target material characteristics are encoded as a cost function, which is minimized on quantum hardware to prepare a many-body state with the desired properties in quantum memory. Hamiltonian learning is then used to reconstruct a low-energy Hamiltonian for which this state is an approximate ground state, yielding a physically interpretable model that can guide experimental synthesis. As illustrative applications, I will discuss how the method can be used to search for high-temperature superconductors within the fermionic Hubbard model, enhancing d-wave correlations over a broad range of dopings and temperatures. I will then present routes towards the design of Hamiltonians leading to genuine quantum phases using deep circuits that involve measurement and qubit recent and have natural implementations on fault-tolerant hardware. I will conclude with discussing extensions of the method for optimizing dynamical properties relevant for photochemistry and frequency- and momentum-resolved condensed-matter data. Our results extend the scope of quantum simulators from exploring quantum many-body systems to designing and discovering new quantum materials.

Rydberg-atom quantum processing units (QPUs) operated in analog mode provide a versatile platform for simulating two-dimensional transverse-field Ising models (TFIM), offering continuous-time dynamics, flexible geometries, and controlled noise. In this talk, we present large-scale quantum simulations of post-quench dynamics near the quantum critical point of the 2D TFIM on square lattices ranging from 64 to 256 sites. The early-time spread of correlations allows us to benchmark the QPU against state-of-the-art tensor network methods, with a focus on noise effects and the limitations of classical approaches. At longer times, where numerical simulations become intractable for 256 sites, the QPU reveals regimes of fast and slow relaxation of local observables toward thermal equilibrium. We also report quantum simulations of a frustrated magnet on a triangular lattice, comparing our results with magnetization data from solid-state experiments and with classical calculations. Finally, we use the QPU to probe nonequilibrium dynamics that are inaccessible to condensed-matter experiments and extremely challenging for numerical methods at these system sizes. Our work demonstrates the power of programmable quantum simulators for studying two-dimensional quantum magnetism and nonequilibrium phenomena.

Lattice gauge theories (LGTs) describe a broad range of phenomena in condensed matter and particle physics. A prominent example is confinement, responsible for bounding quarks inside hadrons such as protons or neutrons. When quark-antiquark pairs are separated, the energy stored in the string of gluon fields connecting them grows linearly with their distance, until there is enough energy to create new pairs from the vacuum and break the string. While such phenomena are ubiquitous in LGTs and play a prominent role in particle-physics experiments, simulating the resulting dynamics is a challenging task. In this talk, I will report the observation of string breaking using a programmable quantum simulator based on neutral atom arrays [Nature 642, 321–326 (2025)]. I will first show how a (2+1)D LGT with dynamical matter can be efficiently encoded using a system of Rydberg atoms, where a U(1) gauge symmetry emerges from the Rydberg blockade mechanism, while long-range Rydberg interactions naturally give rise to a linear confining potential between pairs of charges. In the experiment, we probe string breaking in equilibrium by adiabatically preparing the ground state of the atom array in the presence of defects. Finally, we quench string states and observe string breaking dynamics exhibiting a many-body resonance phenomenon. As an outlook, I will present a roadmap to further explore phenomena in high-energy physics, such as string roughening [arXiv:2602.06123 (2026)], using programmable quantum simulators.