Dynamics of open quantum systems with initial system-environment correlations via stochastic unravelings




Settimo, Federico; Luoma, Kimmo; Chruściński, Dariusz; Smirne, Andrea; Vacchini, Bassano; Piilo, Jyrki

PublisherAmerican Physical Society

2025

 Physical Review A

042204

112

4

2469-9926

2469-9934

DOIhttps://doi.org/10.1103/q353-4232

https://doi.org/10.1103/q353-4232

https://arxiv.org/abs/2502.12818

https://arxiv.org/abs/2502.12818v1



In standard treatments of open quantum systems, the reduced dynamics is described starting from the assumption that the system and the environment are initially uncorrelated. This assumption, however, is not always guaranteed in realistic scenarios and several theoretical approaches to characterize initially correlated dynamics have been introduced. For the uncorrelated scenario, stochastic unravelings are a powerful tool to simulate the dynamics. So far they have not been used in the most general case in which correlations are initially present since they cannot be applied to nonpositive operators or noncompletely positive maps. In our work, we employ the bath positive (B+) or one-sided positive decomposition (OPD) formalism as a starting point to generalize stochastic unraveling in the presence of initial correlations. Noticeably, our approach does not depend on the particular unraveling technique, but holds for both piecewise deterministic and diffusive unravelings. This generalization allows not only for more powerful simulations for the reduced dynamics, but also for a deeper theoretical understanding of open system dynamics.


F.S. acknowledges support from Magnus Ehrnroothin Säätiö. A.S. and B.V. acknowledge support from MUR and Next Generation EU via the PRIN 2022 Project “Quantum Reservoir Computing (QuReCo)” (contract n. 2022FEXLYB) and the NQSTI-Spoke1-BaC project QSynKrono (contract n. PE00000023-QuSynKrono). D.C. was supported by the Polish National Science Center under Project No. 2018/30/A/ST2/00837.


Last updated on 25/11/2025 11:03:05 AM