Persistent entanglement in a class of eigenstates of quantum Heisenberg spin glasses

Abstract

The eigenstates of a quantum spin glass Hamiltonian with long-range interaction are examined from the point of view of localisation and entanglement. In particular, low particle sectors are examined and an anomalous family of eigenstates is found that is more delocalised but also has larger inter-spin entanglement. These are then identified as particle-added eigenstates from the one-particle sector. This motivates the introduction and the study of random promoted two-particle states, and it is shown that they may have large delocalisation such as generic ran- dom states and scale exactly like them. However, the entanglement as measured by two-spin concurrence displays different scaling with the total number of spins. This shows how for different classes of complex quantum states entanglement can be qualitatively different even if localisation measures such as participation ratio are not.

7 pages, 3 figures, 1 table

References in corpus (11)

• Quantum Communication through Spin Chain Dynamics: an Introductory Overview
• Quantum chaos and thermalization in gapped systems
• Entangling power of the quantum baker's map
• Finite-Size Scaling Analysis of the Eigenstate Thermalization Hypothesis in a One-Dimensional Interacting Bose gas
• Global characteristics of all eigenstates of local many-body Hamiltonians: participation ratio and entanglement entropy
• Entanglement, avoided crossings and quantum chaos in an Ising model with a tilted magnetic field
• Entanglement Across a Transition to Quantum Chaos
• Quantum Chaos, Delocalization, and Entanglement in Disordered Heisenberg Models
• Generalized entanglement as a framework for complex quantum systems: Purity vs delocalization measures
• Local entanglement structure across a many-body localization transition
• Entanglement between two subsystems, the Wigner semicircle and extreme value statistics

Cited by in corpus (3)

• Entanglement contour perspective for strong area law violation in a disordered long-range hopping model
• Study of counterintuitive transport properties in the Aubry-André-Harper model via entanglement entropy and persistent current
• Estimation of entanglement in bipartite systems directly from tomograms