Quantum fluctuations and correlations in open quantum Dicke models

Boneberg, Mario; Lesanovsky, Igor; Carollo, Federico

Abstract

In the vicinity of ground-state phase transitions quantum correlations can display nonanalytic behavior and critical scaling. This signature of emergent collective effects has been widely investigated within a broad range of equilibrium settings. However, under nonequilibrium conditions, as found in open quantum many-body systems, characterizing quantum correlations near phase transitions is challenging. Moreover, the impact of local and collective dissipative processes on quantum correlations is not broadly understood. Here we consider as a paradigmatic setting the superradiant phase transition of the open quantum Dicke model and characterize quantum and classical correlations across the phase diagram. We develop an approach to quantum fluctuations which allows us to show that local dissipation, which cannot be treated within the commonly employed Holstein-Primakoff approximation, rather unexpectedly leads to an enhancement of collective quantum correlations, and to the emergence of a nonequilibrium superradiant phase in which the bosonic and spin degrees of freedom of the Dicke model are entangled.

Citation

Boneberg, M., Lesanovsky, I., & Carollo, F. (2022). Quantum fluctuations and correlations in open quantum Dicke models. Physical Review A, 106(1), Article 012212. https://doi.org/10.1103/PhysRevA.106.012212

• Journal Article Type: Article
• Acceptance Date: Jun 29, 2022
• Online Publication Date: Jul 19, 2022
• Publication Date: Jul 1, 2022
• Deposit Date: Jul 25, 2022
• Publicly Available Date: Aug 16, 2022
• Journal: Physical Review A
• Print ISSN: 2469-9926
• Electronic ISSN: 2469-9934
• Publisher: American Physical Society (APS)
• Peer Reviewed: Peer Reviewed
• Volume: 106
• Issue: 1
• Article Number: 012212
• DOI: https://doi.org/10.1103/PhysRevA.106.012212
• Public URL: https://nottingham-repository.worktribe.com/output/9093399
• Publisher URL: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.106.012212