Two-spin and multi-spin quantum entanglement in V12 polyoxovanadate molecular nanomagnet

TL;DR

This study computationally investigates quantum entanglement in a V12 molecular magnet, highlighting how anisotropy and quantum level crossings influence entanglement properties at low temperatures.

Contribution

It provides a detailed analysis of two-spin and four-spin entanglement in V12 cluster magnets using analytical and numerical methods, emphasizing anisotropy effects.

Findings

Entanglement is significantly affected by interaction anisotropy.

Quantum level crossings play a crucial role in entanglement behavior.

Both concurrence and fidelity effectively measure different types of entanglement.

Abstract

The paper reports a computational study of the quantum entanglement in V12 cluster molecular magnet. The low-temperature properties of the system are modelled with anisotropic quantum Heisenberg model on a tetramer of spins $S=1/2$ in the external magnetic field. The two-spin entanglement is quantified using the concurrence, whereas the fidelity serves as a measure of four-spin entanglement. The analytic and numerical results are derived and discussed, emphasizing the importance of real-space and spin-space interaction anisotropy and the role of quantum level crossings in the entanglement description in V12.