Signatures of Associative Memory Behavior in a Multimode Dicke Model

Fiorelli, Eliana; Marcuzzi, Matteo; Rotondo, Pietro; Carollo, Federico; Lesanovsky, Igor

Abstract

© 2020 American Physical Society. Dicke-like models can describe a variety of physical systems, such as atoms in a cavity or vibrating ion chains. In equilibrium these systems often feature a radical change in their behavior when switching from weak to strong spin-boson interaction. This usually manifests in a transition from a "dark"to a "superradiant"phase. However, understanding the out-of-equilibrium physics of these models is extremely challenging, and even more so for strong spin-boson coupling. Here we show that the nonequilibrium strongly interacting multimode Dicke model can mimic some fundamental properties of an associative memory - a system which permits the recognition of patterns, such as letters of an alphabet. Patterns are encoded in the couplings between spins and bosons, and we discuss the dynamics of the spins from the perspective of pattern retrieval in associative memory models. We identify two phases, a "paramagnetic"and a "ferromagnetic"one, and a crossover behavior between these regimes. The "ferromagnetic"phase is reminiscent of pattern retrieval. We highlight similarities and differences with the thermal dynamics of a Hopfield associative memory and show that indeed elements of "machine learning behavior"emerge in the strongly coupled multimode Dicke model.

Citation

Fiorelli, E., Marcuzzi, M., Rotondo, P., Carollo, F., & Lesanovsky, I. (2020). Signatures of Associative Memory Behavior in a Multimode Dicke Model. Physical Review Letters, 125(7), Article 070604. https://doi.org/10.1103/physrevlett.125.070604

• Journal Article Type: Article
• Acceptance Date: Jul 17, 2020
• Online Publication Date: Aug 12, 2020
• Publication Date: Aug 14, 2020
• Deposit Date: Jul 19, 2020
• Publicly Available Date: Aug 12, 2020
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 125
• Issue: 7
• Article Number: 070604
• DOI: https://doi.org/10.1103/physrevlett.125.070604
• Keywords: General Physics and Astronomy
• Public URL: https://nottingham-repository.worktribe.com/output/4777861
• Publisher URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.070604