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arXiv · 1905.05782

Disentangling Sources of Quantum Entanglement in Quench Dynamics

Lorenzo Pastori·Markus Heyl·Jan Carl Budich
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Abstract

Quantum entanglement may have various origins ranging from solely interaction-driven quantum correlations to single-particle effects. Here, we explore the dependence of entanglement on time-dependent single-particle basis transformations in fermionic quantum many-body systems, thus aiming at isolating single-particle sources of entanglement growth in quench dynamics. Using exact diagonalization methods, for paradigmatic non-integrable models we compare to the standard real space cut various physically motivated bipartitions. Moreover, we search for a minimal entanglement basis using local optimization algorithms, which at short to intermediate post-quench times yields a significant reduction of entanglement beyond a dynamical Hartree-Fock solution. In the long-time limit, we identify an asymptotic universality of entanglement for weakly interacting systems, as well as a cross-over from dominant real-space to momentum-space entanglement in Hubbard-models undergoing an interaction quench. Finally, we discuss the relevance of our findings for the development of tensor network based algorithms for quantum dynamics.

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Lorenzo Pastori, Markus Heyl, Jan Carl Budich. 2019-05-14. Disentangling Sources of Quantum Entanglement in Quench Dynamics. https://doi.org/10.1103/physrevresearch.1.012007

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