Magnetic Properties and Thermal Entanglement on a Triangulated Kagome Lattice

TL;DR

This paper investigates the magnetic and thermal entanglement properties of a spin-1/2 Ising-Heisenberg model on a triangulated Kagome lattice, revealing how quantum entanglement and magnetic features coexist and depend on temperature, magnetic field, and coupling.

Contribution

It introduces a variational mean-field approach to analyze quantum entanglement in a complex lattice, highlighting the coexistence of entangled and disentangled phases in different magnetic states.

Findings

Concurrence remains non-zero without magnetic field.

Magnetic and entanglement features show common plateau and peak behaviors.

Critical and threshold temperatures for phase transition and entanglement coincide.

Abstract

The magnetic and entanglement thermal (equilibrium) properties in spin-1/2 Ising-Heisenberg model on a triangulated Kagome lattice are analyzed by means of variational mean-field like treatment based on Gibbs-Bogoliubov inequality. Because of the separable character of Ising-type exchange interactions between the Heisenberg trimers the calculation of quantum entanglement in a self-consistent field can be performed for each of the trimers individually. The concurrence in terms of three qubit isotropic Heisenberg model in effective Ising field is non-zero even in the absence of a magnetic field. The magnetic and entanglement properties exhibit common (plateau and peak) features observable via (antferromagnetic) coupling constant and external magnetic field. The critical temperature for the phase transition and threshold temperature for concurrence coincide in the case of antiferromagnetic coupling between qubits. The existence of entangled and disentangled phases in saturated and frustrated phases is established.