Pairwise entanglement in the XX model with a magnetic impurity

Abstract

For a 3-qubit Heisenberg model in a uniform magnetic field, the pairwise thermal entanglement of any two sites is identical due to the exchange symmetry of sites. In this paper we consider the effect of a non-uniform magnetic field on the Heisenberg model, modeling a magnetic impurity on one site. Since pairwise entanglement is calculated by tracing out one of the three sites, the entanglement clearly depends on which site the impurity is located. When the impurity is located on the site which is traced out, that is, when it acts as an external field of the pair, the entanglement can be enhanced to the maximal value 1; while when the field acts on a site of the pair the corresponding concurrence can only be increased from 1/3 to 2/3.

9 Pages, 4 EPS figures, LaTeX 2e

References in corpus (7)

• Entanglement in the Quantum Heisenberg XY model
• Quantum Entanglement in Fermionic Lattices
• Quantum Correlations in Two-Fermion Systems
• Thermal concurrence mixing in a 1D Ising model
• Effects of anisotropy on thermal entanglement
• Entanglement in a two-identical-particle system
• Thermal entanglement in three-qubit Heisenberg models

Cited by in corpus (10)

• Boundary and impurity effects on entanglement of Heisenberg chains
• Unconventional strengthening of a bipartite entanglement of a mixed spin-(1/2,1) Heisenberg dimer achieved through Zeeman splitting
• Nonequilibrium thermal entanglement in three-qubit $XX$ model
• Quantum entanglement dynamics and decoherence wave in spin chains at finite temperatures
• On the effects of an impurity in an Ising-$XXZ$ diamond chain on the thermal entanglement, on the quantum coherence and on the quantum teleportation
• Quantum coherence, quantum Fisher information and teleportation in the Ising-Heisenberg spin chain model of a heterotrimetallic Fe-Mn-Cu coordination polymer with magnetic impurity
• The entanglement in one-dimensional random XY spin chain with Dzyaloshinskii-Moriya interaction
• Entanglement control in one-dimensional $s=1/2$ random XY spin chain
• Thermal quantum discord in the Heisenberg chain with impurity
• Effects of impurity on fidelity of quantum state transfer via spin channels