Pairwise thermal entanglement in Ising-XYZ diamond chain structure in an external magnetic field

TL;DR

This paper investigates the thermal entanglement properties of an Ising-XYZ diamond chain structure under an external magnetic field, revealing unusual concurrence behaviors influenced by XY-anisotropy, with implications for real material modeling.

Contribution

It introduces a detailed analysis of thermal entanglement in a complex diamond chain structure, highlighting novel concurrence behaviors due to XY-anisotropy in the Heisenberg coupling.

Findings

Unusual concurrence boundary behavior observed.

Disentangled regions emerge due to XY-anisotropy.

Model applicable to real material structures.

Abstract

Quantum entanglement is one of the most fascinating types of correlation that can be shared only among quantum systems. The Heisenberg chain is one of the simplest quantum chains which exhibits a reach entanglement feature, due to the Heisenberg interaction is quantum coupling in the spin system. The two particles were coupled trough XYZ coupling or simply called as two-qubit XYZ spin, which are the responsible for the emergence of thermal entanglement. These two-qubit operators are bonded to two nodal Ising spins, and this process is repeated infinitely resulting in a diamond chain structure. We will discuss two-qubit thermal entanglement effect on Ising-XYZ diamond chain structure. The concurrence could be obtained straightforwardly in terms of two-qubit density operator elements, using this result, we study the thermal entanglement, as well as the threshold temperature where entangled state vanishes. The present model displays a quite unusual concurrence behavior, such as, the boundary of two entangled regions becomes a disentangled region, this is intrinsically related to the XY-anisotropy in the Heisenberg coupling. Despite a similar property had been found for only two-qubit, here we show in the case of a diamond chain structure, which reasonably represents real materials.