Entanglement of finite cyclic chains at factorizing fields

Abstract

We examine the entanglement of cyclic spin 1/2 chains with anisotropic XY Z Heisenberg couplings of arbitrary range at transverse factorizing magnetic fields. At these fields the system exhibits a degenerate symmetry-breaking separable ground state (GS). It is shown, however, that the side limits of the GS pairwise entanglement at these fields are actually non-zero in finite chains, corresponding such fields to a GS spin-parity transition. These limits exhibit universal properties like being independent of the pair separation and interaction range, and are directly related to the magnetization jump. Illustrative exact results are shown for chains with I) full range and II) nearest neighbor couplings. Global entanglement properties at such points are also discussed.

5 pages, 4 figures

References in corpus (5)

• General Monogamy Inequality for Bipartite Qubit Entanglement
• Entanglement and factorized ground states in two-dimensional quantum antiferromagnets
• Divergence of the entanglement range in low dimensional quantum systems
• Two-spin entanglement distribution near factorized states
• Description of thermal entanglement with the static path plus random-phase approximation

Cited by in corpus (8)

• Separability and ground state factorization in quantum spin systems
• Ground-state factorization and quantum phase transition in dimerized spin chains
• Entanglement quantification by local unitaries
• Separability and entanglement in finite dimer-type chains in general transverse fields
• Evaluation of ground state entanglement in spin systems with the random phase approximation
• Evaluation of pairwise entanglement in translationally invariant systems with the random phase approximation
• Even-odd entanglement in boson and spin systems
• Entanglement and symmetry effects in the transition to the Schroedinger cat regime