Restricted Monte Carlo wave-function method and Lindblad equation for identifying entangling open-quantum-system dynamics
Phys. Rev. A 113, 012220 – Published 16 January, 2026
DOI: https://doi.org/10.1103/hcj7-8zlg
Abstract
We develop an extension of the Monte Carlo wave-function approach that unambiguously identifies dynamical entanglement in general composite, open systems. Our algorithm performs tangential projections onto the set of separable states, leading to classically correlated quantum trajectories. By comparing this restricted evolution with the unrestricted one, we can characterize the entangling capabilities of quantum channels without making use of input-output relations. Moreover, applying this method is equivalent to solving the nonlinear master equation in Lindblad form introduced in Pinske et al., Phys. Rev. A 113, L010403 (2026) for two-qubit systems. Our approach also provides a necessary and sufficient condition for entanglement in multipartite systems of arbitrary size, in terms of a stochastic differential equation. Thereby, we isolate the impact of dynamical entanglement in open systems by applying our approach to several correlated decay processes. Therefore, our methodology provides a complete and ready-to-use framework to characterize dynamical quantum correlations caused by arbitrary open-system processes.
