2018/12/02 by S. E. B. Nielsen, C. Schäfer, Nielsen, S. E. B. +5
Computer Science · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Strong Light-Matter Interactions
paper · pdf · doi:10.48550/arxiv.1812.00388
openalex publication_date 2018/12/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a novel representation of coupled matter-photon systems that allows the application of many-body methods developed for purely fermionic systems. We do so by rewriting the original coupled light-matter problem in a higher-dimensional configuration space and then use photon-dressed orbitals as a basis to expand the thus "fermionized" coupled system. As an application we present a dressed time-dependent density-functional theory approach. The resulting dressed Kohn-Sham scheme allows for straightforward non-adiabatic approximations to the unknown exchange-correlation potential that explicitly includes correlations. We illustrate this for simple model systems placed inside a high-Q optical cavity, and show also results for observables such as the photon-field fluctuations that are hard to capture in standard matter-photon Kohn-Sham. We finally highlight that the dressed-orbital approach extends beyond the context of cavity quantum electrodynamics and can be applied to, e.g., van-der-Waals problems.