Absence of Entanglement Growth in Dicke Superradiance

• URL: http://arxiv.org/abs/2504.13646v2
• Date: Mon, 28 Apr 2025 00:57:26 GMT
• Title: Absence of Entanglement Growth in Dicke Superradiance
• Authors: Nico S. Bassler,
• Abstract summary: Dicke superradiance describes an ensemble of $N$ permutationally invariant two-level systems collectively emitting radiation with a peak radiated intensity scaling as $N2$.<n>Although individual Dicke states are typically entangled, the density matrix during superradiant decay is a mixture of such states, raising the subtle question of whether the total state is entangled or separable.<n>This answers a longstanding question on the role of entanglement in Dicke superradiance and underscores that, despite collective dissipation, separable states remain separable under these dynamics.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Dicke superradiance describes an ensemble of $N$ permutationally invariant two-level systems collectively emitting radiation with a peak radiated intensity scaling as $N^2$. Although individual Dicke states are typically entangled, the density matrix during superradiant decay is a mixture of such states, raising the subtle question of whether the total state is entangled or separable. We resolve this by showing analytically that for all $N$, starting from the fully excited state, the collective decay preserves separability for all times. This answers a longstanding question on the role of entanglement in Dicke superradiance and underscores that, despite collective dissipation, separable states remain separable under these dynamics.

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