Permutation-symmetric quantum trajectories

• URL: http://arxiv.org/abs/2605.11103v2
• Date: Sat, 16 May 2026 10:01:18 GMT
• Title: Permutation-symmetric quantum trajectories
• Abstract summary: We show how one may perform a unraveling which respects weak permutation symmetry for models of $N$ emitters coupled to a common system.<n>For problems involving 2-level emitters, such an unravelling reduces the computational cost from $mathcalO(N5)$ to $mathcalO(N2)$.
• Score: 42.05677589454327
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We show how one may perform a stochastic unraveling which respects weak permutation symmetry for models of $N$ emitters coupled to a common system (e.g. a cavity mode). For problems involving 2-level emitters, such an unravelling reduces the computational cost from $\mathcal{O}(N^5)$ to $\mathcal{O}(N^2)$, and with additional refinements, allows reduction to $\mathcal{O}(N)$. This significantly increases the range of system sizes for which one can model exact quantum dynamics of such systems. We further show how the method can also be applied to d-level systems, with computational effort scaling as $\mathcal{O}(N^{d(d-1)/2})$, and we show it allows large-N simulations for d=3.

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