Generalized stochastic spin-wave theory for open quantum spin systems
Phys. Rev. B 113, 214324 – Published 24 June, 2026
DOI: https://doi.org/10.1103/d942-3lmt
Abstract
We propose a semiclassical framework for solving open quantum dynamics in driven-dissipative spin systems. Our method consists of generalized spin-wave approximations tailored to describing quantum trajectories unraveled from the master equation, and it generically applies to regimes beyond the reach of conventional spin-wave theories, including short-range interactions and local quantum jumps, enabling the efficient simulation of large-scale interacting spins. We illustrate the versatility of our framework by studying a variable-range driven-dissipative Ising model on a two-dimensional lattice. When the dissipation acts along the drive axis, we find a continuous phase transition breaking the symmetry, and we demonstrate that the interaction range, when tuned from fully connected to nearest-neighbor, profoundly alters the universality class of the criticality. With the dissipation along the interaction axis, we show the emergence of a first-order transition. Demonstrated with both state-diffusion and quantum-jump types of trajectory dynamics, our framework provides a powerful toolbox for the efficient semiclassical description of nonequilibrium dynamics and many-body phases in spin systems.
