Directly observing replica symmetry breaking in a vector quantum-optical spin glass

Science (2025)

In spin glasses, disorder and geometric frustration cause exact system copies called replicas to relax into distinct configurations. These configurations have overlaps that form a hierarchic, tree-like structure that is referred to as ultrametric. In this paper, scientists used ultracold gases of rubidium atoms trapped in optical tweezers and placed them in a cavity to visualize the ultrametric structure of a glassy system. The driven-dissipative nature of the system further enriched the spin glass phenomenology.

The paper’s authors are Ronen M. Kroeze, Brendan P. Marsh, David Atri Schuller, Henry S. Hunt, Alexander N. Bourzutschky, Michael Winer, Sarang Gopalakrishnan, Jonathan Keeling and Benjamin L. Lev, who conducted their work at Stanford University, the University of Maryland, Princeton University and the University of St. Andrews.