Speaker: Diego Fallas Padilla, Rice University

Title: The quantum Rabi ring and its connections to quantum magnetism

Abstract: It is not unusual that two seemingly very different systems are connected by the same underlying physics. Finding such connections can often help us gain new insights into one system by importing knowledge obtained from the study of the other. Here we show how a light-matter interacting system, named the quantum Rabi ring, can be mapped to a magnetic system with various types of magnetic exchange couplings, allowing us to study the analog of ferromagnetic and antiferromagnetic ordering, as well as chiral magnetic structures, like magnetic vortices, in this quantum optics platform. We study how the geometry of the ring affects the phase diagram of the model. Specifically, when the system contains an odd number of sites, geometrical frustration stabilizes the chiral phases, a behavior well studied in antiferromagnetic systems, allowing us to find an optical equivalent of the magnetic frustration phenomenon. This frustration not only generates a highly degenerate ground state but causes anomalous scaling exponents in the vicinity of the phase boundary. This work not only introduces a new candidate for simulation of few-body classical magnetic systems, but also emphasizes how we can use our accumulated knowledge of magnetic systems to explain features of systems that might not seem to be related to the former, at least at first glance.