Long-range frustrating interactions, even if their strength is infinitesimal, can give rise to a dramatic proliferation of ground or near-ground states. As a consequence, the ordering temperature can exhibit a discontinuous drop as a function of the frustration. We have found this phenomenon in an entire class of models: amphiphilic systems, Mott insulators, and gauge theories of metallic glasses, to name a few.

• Received 12 October 1998

DOI:https://doi.org/10.1103/PhysRevLett.83.472