Light-matter interactions in the vacuum of ultrastrongly coupled systems

Year: 2024

Authors: De Bernardis D., Andolina G.M., Carusotto I.

Autors Affiliation: INO CNR, Pitaevskii BEC Ctr, I-38123 Trento, Italy; Univ TrentoI, Dipartimento Fis, Trento, Italy; PSL Res Univ, Coll France, JEIP, UAR CNRS 3573, 11 Pl Marcelin Berthelot, F-75321 Paris, France; Natl Inst Opt Consiglio Nazl Ric CNR INO, Care European Lab Nonlinear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy.

Abstract: We theoretically study how the peculiar properties of the vacuum state of an ultrastrongly coupled system can affect basic light-matter interaction processes. In this unconventional electromagnetic environment, an additional emitter no longer couples to the bare cavity photons, but rather to the polariton modes emerging from the ultrastrong coupling. As such, the effective light-matter interaction strength is sensitive to the properties of the distorted vacuum state. Different interpretations of our predictions in terms of modified quantum fluctuations in the vacuum state and of radiative reaction in classical electromagnetism are critically discussed. Whereas our discussion is focused on the experimentally most relevant case of intersubband polaritons in semiconductor devices, our framework is fully general and applies to generic material systems.

Journal/Review: PHYSICAL REVIEW A

Volume: 110 (5)      Pages from: 53713-1  to: 53713-23

More Information: We are grateful to R. Colombelli, F. Pisani, Y. Todorov, M. Schiro, S. De Liberato, P, Rabl, and G. La Rocca for useful discussions. We acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 101002955, CONQUER), from the Provincia Autonoma di Trento, the Q@TN initiative, and the PNRR MUR Project No. PE0000023-NQSTI. D.D.B. acknowledges funding from the European Union-NextGeneration EU, Integrated infrastructure initiative in Photonic and Quantum Sciences-I-PHOQS [IR0000016, ID D2B8D520, CUP B53C22001750006].
KeyWords: Spontaneous-emission; Quantum Electrodynamics; Radiation-reaction; Field; Absorption; Forces; Atoms
DOI: 10.1103/PhysRevA.110.053713