Logarithmic negativity in out-of-equilibrium open free-fermion chains: An exactly solvable case

We derive the quasiparticle picture for the fermionic logarithmic negativity in a tight-binding chain subject to gain and loss dissipation. We focus on the dynamics after the quantum quench from the fermionic Néel state. We consider the negativity between both adjacent and disjoint intervals embedde...

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Bibliographic Details
Published in:SciPost Physics
Main Author: Vincenzo Alba, Federico Carollo
Format: Article
Language:English
Published: SciPost 2023-09-01
Online Access:https://scipost.org/SciPostPhys.15.3.124
Description
Summary:We derive the quasiparticle picture for the fermionic logarithmic negativity in a tight-binding chain subject to gain and loss dissipation. We focus on the dynamics after the quantum quench from the fermionic Néel state. We consider the negativity between both adjacent and disjoint intervals embedded in an infinite chain. Our result holds in the standard hydrodynamic limit of large subsystems and long times, with their ratio fixed. Additionally, we consider the weakly-dissipative limit, in which the dissipation rates are inversely proportional to the size of the intervals. We show that the negativity is proportional to the number of entangled pairs of quasiparticles that are shared between the two intervals, as is the case for the mutual information. Crucially, in contrast with the unitary case, the negativity content of quasiparticles is not given by the Rényi entropy with Rényi index $1/2$, and it is in general not easily related to thermodynamic quantities.
ISSN:2542-4653