  Artificial spin ices are frustrated spin systems that can be engineered,
wherein fine tuning of geometry and topology has allowed the design and
characterization of exotic emergent phenomena at the constituent level. Here we
report a realization of spin ice in a lattice of superconducting qubits. Unlike
conventional artificial spin ice, our system is disordered by both quantum and
thermal fluctuations. The ground state is classically described by the ice
rule, and we achieve control over a fragile degeneracy point leading to a
Coulomb phase. The ability to pin individual spins allows us to demonstrate
Gauss's law for emergent effective monopoles in two dimensions. The
demonstrated qubit control lays the groundwork for potential future study of
topologically protected artificial quantum spin liquids.
