One-to-one quantum simulation of the low-dimensional frustrated quantum magnet TmMgGaO₄ with 256 qubits

Low-dimensional materials exhibit exotic properties due to enhanced quantum fluctuations, making the understanding of their microscopic origin central in condensed matter physics. Analogue quantum simulators offer a powerful approach for investigating these systems at the microscopic level, particularly in large-scale regimes where quantum entanglement limits classical numerical methods. To date, analogue simulators have largely focused on universal Hamiltonians rather than material-specific quantitative comparisons. Here we use a Rydberg-based quantum simulator to study the bulk-layered frustrated quantum magnet TmMgGaO₄. Magnetisation measurements obtained from the quantum simulator show excellent agreement with independent measurements performed in a magnetic laboratory facility, validating the proposed effective two-dimensional microscopic Hamiltonian. Building on this quantitative correspondence, we investigate on both platforms the antiferromagnetic phase transition. We further probe the role of quantum fluctuations via snapshot analysis, connecting our results to integrated inelastic neutron scattering data. Finally, we access, with the simulator, non-equilibrium dynamics on picosecond material timescales, including frequency response and thermalisation of observables.