2026/08/01 by Ruiyang Huang, Eliott Beraud, Antoine Glicenstein +1
Physics and Astronomy · #quant-ph
18 pages, 8 figures. Submitted to PRX
arxiv created 2026/08/01 · arxiv updated 2026/08/04
Pure quantum states, as described in quantum mechanics textbooks, are ideal representations inevitably deteriorated in real systems by any dissipative connection to the environment. In this work we derive a unified theoretical frame to study the non-Hermitian dynamics of a driven-dissipative quantum system and validate it by comparison to experimental data of matter-wave diffraction. To highlight the role of dissipation, we perform the comparison in a near-resonant regime of light-matter interaction, where perturbative approaches fail. Here, we show that the developed formalism enables both exact simulations and an intuitive interpretation based on modal analysis. The theoretical analysis is based on the general master equation description of driven-dissipative systems, from which we derive an effective complex potential Veff(Ω,Δ) that depends on control parameters such as the amplitude and detuning of the light matter interaction. Experimentally, we drive a 87Rb BEC near resonance using periodic excited-state engineering, mapping the spatially modulated V\rm eff[Ω,Δ(x)] into momentum space for precise quantification. The experimental results agree with numerical simulations of the master equation and demonstrate the interplay between coherent drive and dissipation, with an exceptional signature: a reduced decay rate with increasing drive. Such dynamics is then interpreted by a modal analysis of the non-Hermitian Hamiltonian Heff=p2/2m+Veff which provide an intuitive and qualitative explanation for such driven-dissipative system.