Defining the Semiclassical Limit of the Quantum Rabi Hamiltonian

Irish, E. K.; Armour, A. D.

Abstract

The crossover from quantum to semiclassical behavior in the seminal Rabi model of light-matter interaction still, surprisingly, lacks a complete and rigorous understanding. A formalism for deriving the semiclassical model directly from the quantum Hamiltonian is developed here. Working in a displaced Fock-state basis |α,n|, the semiclassical limit is obtained by taking |α|→∞ and the coupling to zero. This resolves the discrepancy between coherent-state dynamics and semiclassical Rabi oscillations in both standard and ultrastrong coupling and driving regimes. Furthermore, it provides a framework for studying the quantum-to-semiclassical transition, with potential applications in quantum technologies.

Citation

Irish, E. K., & Armour, A. D. (2022). Defining the Semiclassical Limit of the Quantum Rabi Hamiltonian. Physical Review Letters, 129(18), Article 183603. https://doi.org/10.1103/PhysRevLett.129.183603

• Journal Article Type: Article
• Acceptance Date: Sep 19, 2022
• Online Publication Date: Oct 26, 2022
• Publication Date: Oct 28, 2022
• Deposit Date: Sep 21, 2022
• Publicly Available Date: Oct 26, 2022
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society (APS)
• Peer Reviewed: Peer Reviewed
• Volume: 129
• Issue: 18
• Article Number: 183603
• DOI: https://doi.org/10.1103/PhysRevLett.129.183603
• Keywords: General Physics and Astronomy
• Public URL: https://nottingham-repository.worktribe.com/output/11467075
• Publisher URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.183603