Simulating physics of interacting many-body quantum systems is notoriously difficult since the Hilbert space of a compound quantum system grows exponentially fast with the system size. The idea to simulate one physical system with another system that permits better control of both unitary and dissipative dynamics is of great practical value.

Cold, trapped atoms interacting with laser fields represent a remarkably clean and controllable platform to simulate and study many-body physics. A crucial ingredient for realizing various phases of matter is availability of interactions with different range and strength. We employ strong, long-range, switchable interactions between cold atoms excited to the Rydberg states to realize strongly-interacting many-body systems and for implementing various quantum information processing tasks.