Thermal entanglement in the mixed three spin XXZ Heisenberg Model on a triangular cell

TL;DR

This study numerically explores how thermal entanglement in a mixed three-spin XXZ Heisenberg model on a triangular cell is influenced by magnetic fields and temperature, revealing critical points and entanglement plateaus.

Contribution

It provides new insights into the behavior of thermal entanglement in mixed-spin systems under magnetic fields, highlighting phenomena like entanglement plateaus and finite-temperature quantum phase transitions.

Findings

Magnetic field induces strong entanglement plateaus.

Unexpected finite-temperature critical point in antiferromagnetic case.

Entanglement decays exponentially with temperature in most cases.

Abstract

We numerically investigate thermal entanglement of the spins (1/2,1) and (1/2,1/2) in the three-mixed (1/2,1,1/2) anisotropic Heisenberg XXZ spin system on a simple triangular cell under an inhomogeneous magnetic field. We show that the external magnetic field induces strong plateau formation in pairwise thermal entanglement for fixed parameters of Hamiltonian in the case of the ferromagnetic and anti-ferromagnetic interactions. We also observe an unexpected critical point at finite temperature in the thermal entanglement of the spins (1/2,1) for antiferromagnetic case while the entanglement of the spins (1/2,1) for ferromagnetic case and the entanglement of the spins (1/2,1/2) for both ferromagnetic and antiferromagnetic cases almost decays exponentially to zero with increasing temperature. The critical point in entanglement of the spins (1/2,1) for antiferromagnetic case may be signature of the quantum phase transition at finite temperature.