Work

Lee-Yang theory of the superradiant phase transition in the open Dicke model

Year: 2024

Type: article

Abstract: The Dicke model describes an ensemble of two-level atoms that are coupled to a confined light mode of an optical cavity. Above a critical coupling, the cavity becomes macroscopically occupied, and the system enters the superradiant phase. This phase transition can be observed by detecting the photons that are emitted from the cavity; however, it only becomes apparent in the limit of long observation times, while actual experiments are of a finite duration. To circumvent this problem, we here make use of recent advances in Lee-Yang theories of phase transitions to show that the superradiant phase transition can be inferred from the factorial cumulants of the photon emission statistics obtained during a finite measurement time. Specifically, from the factorial cumulants, we can determine the complex singularities of generating functions that describe the photon emission statistics, and by extrapolating their positions to the long-time limit one can detect the superradiant phase transition. We also show that the convergence points determine the tails of the large-deviation statistics of the photon current. Our paper demonstrates how phase transitions in the Dicke model and in other quantum many-body systems can be detected from measurements of a finite duration. Published by the American Physical Society 2024

Source: Physical Review Research

DOI: 10.1103/physrevresearch.6.033181

Authors: Fredrik Brange, Neill Lambert, Franco Nori, Christian Flindt

Institutions: Aalto University, RIKEN, RIKEN Center for Quantum Computing, University of Michigan

Language: English

Topic: Strong Light-Matter Interactions

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,767