Generalized-hydrodynamic approach to inhomogeneous quenches: correlations, entanglement and quantum effects

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We investigate the entanglement dynamics in a free-fermion chain initially prepared in a Fermi sea and subjected to localized losses (dissipative impurity). We derive a formula describing the dynamics of the entanglement entropies in the hydrodynamic limit of long times and large intervals. The result depends only on the absorption coefficient of the effective delta potential describing the impurity in the hydrodynamic limit. Genuine dissipation-induced entanglement is certified by the linear growth of the logarithmic negativity. Finally, in the quantum Zeno regime at strong dissipation the entanglement growth is arrested (Zeno entanglement death).

Section: Introductionmentioning

confidence: 73%

Unbounded entanglement production via a dissipative impurity

Alba

2022

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“…where we took L even. Quantum quenches from this kind of states are known as bipartitioning protocols [59][60][61][62] and can be thought of as the sudden junction of two homogeneous leads prepared in different states. In this case, the precise expression for the Rényi entropies depends on the position of A with respect to the junction.…”

Section: Entanglement Dynamics In the Time-channelmentioning

confidence: 99%

Entanglement dynamics in Rule 54: Exact results and quasiparticle picture

Klobas

Bertini

2021

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We study the entanglement dynamics generated by quantum quenches in the quantum cellular automaton Rule 54. We consider the evolution from a recently introduced class of solvable initial states. States in this class relax (locally) to a one-parameter family of Gibbs states and the thermalisation dynamics of local observables can be characterised exactly by means of an evolution in space. Here we show that the latter approach also gives access to the entanglement dynamics and derive exact formulas describing the asymptotic linear growth of all Rényi entropies in the thermodynamic limit and their eventual saturation for finite subsystems. While in the case of von Neumann entropy we recover exactly the predictions of the quasiparticle picture, we find no physically meaningful quasiparticle description for other Rényi entropies. Our results apply to both homogeneous and inhomogeneous quenches.

“…The scaling regime of the inhomogeneous quench considered in the previous section is the setup in which GHD applies most directly [11,58,59]. This means that our exact results can be used to provide a, hitherto missing, independent verification of the GHD predictions.…”

Section: Comparison With Ghdmentioning

confidence: 77%

“…Before concluding this general discussion we will show that, besides homogeneous quantum quenches, the formalism described here can be directly applied to two additional physically relevant quench problems -Bipartitioning protocols [10,11,85,86], i.e. quenches from inhomogeneous states that are composed by joining two different homogeneous pieces (or "leads").…”

Section: Time-channel Formulation Of the Local Dynamicsmentioning

confidence: 99%

“…Over the last two decades intense efforts by both experimentalists and theorists have greatly advanced our understanding of isolated quantum matter out of equilibrium [1][2][3][4][5][6][7][8][9]. It is now established that at asymptotically large times expectation values of local observables relax to time-independent numbers in translationally invariant systems [6,9], while they follow slow dynamics governed by emergent classical hydrodynamic equations [10][11][12] when the translational invariance is weakly broken. This surprising onset of relaxation in isolated systems is induced by the effective bath created by the system on its own parts, and the final (quasi) stationary state of the system is determined by the conservation laws with local densities [13].…”

Section: Introductionmentioning

confidence: 99%

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Exact relaxation to Gibbs and non-equilibrium steady states in the quantum cellular automaton Rule 54

Klobas

Bertini

2021

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We study the out-of-equilibrium dynamics of the quantum cellular automaton Rule 54 using a time-channel approach. We exhibit a family of (non-equilibrium) product states for which we are able to describe exactly the full relaxation dynamics. We use this to prove that finite subsystems relax to a one-parameter family of Gibbs states. We also consider inhomogeneous quenches. Specifically, we show that when the two halves of the system are prepared in two different solvable states, finite subsystems at finite distance from the centre eventually relax to the non-equilibrium steady state (NESS) predicted by generalised hydrodynamics. To the best of our knowledge, this is the first exact description of the relaxation to a NESS in an interacting system and, therefore, the first independent confirmation of generalised hydrodynamics for an inhomogeneous quench.