Eigenstate Thermalization in a Locally Perturbed Integrable System

• URL: http://arxiv.org/abs/2004.04755v3
• Date: Thu, 13 Aug 2020 16:53:59 GMT
• Title: Eigenstate Thermalization in a Locally Perturbed Integrable System
• Authors: Marlon Brenes, Tyler LeBlond, John Goold and Marcos Rigol
• Abstract summary: Eigenstate thermalization is widely accepted as the mechanism behind thermalization in isolated quantum systems. We show that locally perturbing an integrable system can give rise to eigenstate thermalization.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Eigenstate thermalization is widely accepted as the mechanism behind thermalization in generic isolated quantum systems. Using the example of a single magnetic defect embedded in the integrable spin-1/2 $XXZ$ chain, we show that locally perturbing an integrable system can give rise to eigenstate thermalization. Unique to such setups is the fact that thermodynamic and transport properties of the unperturbed integrable chain emerge in properties of the eigenstates of the perturbed (nonintegrable) one. Specifically, we show that the diagonal matrix elements of observables in the perturbed eigenstates follow the microcanonical predictions for the integrable model, and that the ballistic character of spin transport in the integrable model is manifest in the behavior of the off-diagonal matrix elements of the current operator in the perturbed eigenstates.

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