Witnessing Nonequilibrium Entanglement Dynamics in a Strongly Correlated Fermionic Chain

Many-body entanglement in condensed matter systems can be diagnosed from equilibrium response functions through the use of entanglement witnesses and operator-specific quantum bounds. Here, we investigate the applicability of this approach for detecting entangled states in quantum systems driven out of equilibrium. We use a multipartite entanglement witness, the quantum Fisher information, to study the dynamics of a paradigmatic fermion chain undergoing a time-dependent change of the Coulomb interaction. Our results show that the quantum Fisher information is able to witness distinct signatures of multipartite entanglement both near and far from equilibrium that are robust against decoherence. We discuss implications of these findings for probing entanglement in light-driven quantum materials with time-resolved optical and x-ray scattering methods.

Automated summary

The applicability of using entanglement witnesses and operator-specific quantum bounds to diagnose many-body entanglement in condensed matter systems is investigated. The study focuses on detecting entangled states in quantum systems driven out of equilibrium. The dynamics of a fermion chain undergoing a time-dependent change of the Coulomb interaction is studied using the multipartite entanglement witness, the quantum Fisher information. The results show that the quantum Fisher information can witness distinct signatures of multipartite entanglement both near and far from equilibrium, and these signatures are robust against decoherence. The findings have implications for probing entanglement in light-driven quantum materials with time-resolved optical and x-ray scattering methods.