Experimental dynamics of a quantum-optical spin glass

We realize a driven-dissipative spin glass in the quantum-optical setting in a multimode degenerate cavity. Ultracold clouds of atoms trapped by optical tweezers serve as effective spins, and a novel "4/7" cavity geometry that we employ engineers a randomly signed, all-to-all, photon-mediated Ising interaction between spins. Microscopic access to the spin states is obtained via holographic imaging of the cavity light in networks of up to n = 25 spins, and the use of a high-speed camera allows for continuous monitoring of the spins evolving in time. We measure spin glass properties such as the overlap distribution between replicas as dynamical quantities, demonstrating how the system orders as a function of time, and observe its ability to perform pattern completion by minimizing the Ising energy, realizing associative memory. The dynamical observability will enable further studies of spin glass phenomena such as aging and rejuvenation with full visibility at the microscopic level.