Collective cluster nucleation dynamics in 2D Ising quantum magnets

Abstract: Strongly interacting many-body systems often show collective properties that are non-trivially related to the microscopic degrees of freedom. Collectivity is responsible for intriguing ground state properties, for example, in superconductors. However, collective effects may also govern the non-equilibrium response of quantum systems, not only in condensed matter physics but also in quantum field theories modeling the properties of our universe. Understanding emergent collective dynamics from first principles, in particular in non-perturbative regimes, is therefore one of the central challenges in quantum many-body physics. Here we report on the observation of collective cluster nucleation in 2D quantum Ising systems realized in an atomic Rydberg array. We observe a confined regime in which the steady-state cluster size is energy-dependent and a deconfined regime characterized by kinetically constrained dynamics of cluster nucleation. Our results mark a qualitative leap for quantum simulations with Rydberg arrays and shed light on highly collective non-equilibrium processes in one of the most important textbook models of condensed matter physics with relevance from quantum magnets and the kinetics of glass formers to cosmology.