Title: An Experimental Quantum-Optical Spin Glass:  From Ultrametricity to Associative Memory

Abstract: Spin glasses are canonical examples of complex matter and form a basis for describing artificial neural networks.  Advancing experimental insight into their structure requires repeatable control over microscopic degrees of freedom.  I will present how we achieved this at the atomic level using a quantum optical system comprised of ultracold gases of atoms coupled via photons resonating within a confocal cavity.  The controllability provided by this new spin-glass system has allowed us to directly measure replica symmetry breaking, yielding an observation of ultrametricity in a physical system.  We use this spin glass to realize an associative memory with a capacity exceeding that of the Hopfield model.

A light lunch will be served in the Bowen Atrium at noon.