Visualizing Quasiparticles from Quantum Entanglement for general 1D phases

TL;DR

This paper introduces a quantum information framework to analyze quasiparticle entanglement in 1D quantum phases, revealing universal features and extending understanding to strongly interacting systems.

Contribution

It establishes an exact correspondence between correlation matrices and quasiparticle entanglement Hamiltonians, and identifies universal entanglement features across 1D phases.

Findings

Exact correlation between correlation matrix and entanglement Hamiltonian

Discovery of in-gap states due to quasiparticle position uncertainty

Identification of universal entanglement features like fragmentation and mutual information

Abstract

In this work, we present a quantum information framework for the entanglement behavior of the low energy quasiparticle (QP) excitations in various quantum phases in one-dimensional (1D) systems. We first establish an exact correspondence between the correlation matrix and the QP entanglement Hamiltonian for free fermions and find an extended in-gap state in the QP entanglement Hamiltonian as a consequence of the position uncertainty of the QP. A more general understanding of such an in-gap state can be extended to a Kramers theorem for the QP entanglement Hamiltonian, which also applies to strongly interacting systems. Further, we present a set of ubiquitous entanglement spectrum features, dubbed entanglement fragmentation, conditional mutual information, and measurement induced non-local entanglement for QPs in 1D symmetry protected topological phases. Our result thus provides a new framework to identify different phases of matter in terms of their QP entanglement.