  We introduce a Bose-Hubbard Hamiltonian with random disordered interactions
as a model to study the interplay of superfluidity and glassiness in a system
of three-dimensional hard-core bosons at half-filling. Solving the model using
large-scale quantum Monte Carlo simulations, we show that these disordered
interactions promote a stable superglass phase, where superflow and glassy
density localization coexist in equilibrium without exhibiting phase
separation. The robustness of the superglass phase is underlined by its
existence in a replica mean-field calculation on the infinite-dimensional
Hamiltonian.
