Dissipative Cavity QED

Luis A. Orozco

Rice

Amit Dey, Manas Kulkarni

By exploiting the nonlinear nature of the Jaynes Cumming interaction, one can get photon population trapping in cavity-QED arrays. However, the unavoidable dissipative effects in a realistic system would destroy the self-trapped state by continuous photon leakage, and the self-trapping remains only as a temporary effect. To circumvent this issue, we aim to achieve an indefinitely long-lived self-trapped steady state rather than a localization with limited lifetime. We show that a careful engineering of drive, dissipation, and Hamiltonian results in achieving indefinitely sustained self-trapping. We show that the intricate interplay between drive, dissipation, and light-matter interaction results in requiring an optimal window of drive strengths in order to achieve such nontrivial steady states. We treat the two-cavity and four-cavity cases by using exact open quantum many-body calculations. Additionally, in the semiclassical limit we scale up the system to a long one-dimensional chain and demonstrate localized and delocalized steady-states in a driven-dissipative cavity-QED lattice. Although our analysis is performed by keeping cavity-QED systems in mind, our work is applicable to other driven-dissipative systems where nonlinearity plays a pivotal role.

Giovanna Bruno, Enrico Busani, Lorenzo Gialli +2 more

Cavity Quantum Electrodynamics (Cavity-QED) offers a powerful framework for controlling light-matter interactions, yet first-principles approaches commonly assume ideal, lossless cavity fields. Here, we introduce a minimal extension to the Pauli-Fierz Hamiltonian that accounts for cavity dissipation through the experimentally accessible cavity quality factor Q. The electromagnetic field is described as a damped harmonic oscillator within the very weak damping approximation. In this framework, cavity losses only enter the light-matter interaction and dipole self-energy terms, without introducing additional photonic degrees of freedom. A time-dependent unitary transformation yields a real-valued Hermitian Hamiltonian that can be incorporated into existing ab-initio QED methods without additional computational cost or changes in scaling. We combined the approach to the QED-CCSD method and investigated the effects of cavity dissipation on the optical spectrum of a p-nitroaniline molecule under strong light-matter coupling. We found that, for realistic quality factors, cavity dissipation can reduce the Rabi splitting by more than 20% compared to the ideal-cavity limit, even though the system remains in the strong-coupling regime. Convergence towards the ideal-cavity limit then requires substantially higher quality factors than those needed to establish strong coupling. These results demonstrate that cavity dissipation can significantly affect polaritonic energetics and highlight the importance of incorporating experimentally realistic cavity losses into quantitative ab-initio Cavity-QED simulations to accurately guide experimental protocols.

W. Lange, Q. A. Turchette, Christina J. Hood +2 more

Stefan Putz