Quantum correlation and coherence in a mononuclear nickel-based molecular Magnet

TL;DR

This study explores quantum correlations and coherence in a nickel-based molecular magnet, demonstrating their persistence at room temperature and potential for quantum information applications beyond entanglement.

Contribution

It provides the first detailed analysis of multiple quantum resources in a real molecular magnet using experimentally estimated parameters.

Findings

Quantum resources persist at room temperature.

Measurement-induced nonlocality and coherence are more robust than entanglement.

Quantum correlations exist even when entanglement vanishes.

Abstract

We investigate the behaviors of thermal entanglement, quantum correlation beyond entanglement namely, measurement-induced nonlocality (MIN) and coherence in a nickel radical molecular magnet (Et3NH)[Ni(hfac)2L], whose spin-spin interactions are well described by the Heisenberg model. Using experimentally estimated coupling parameters, we compute the thermal state of the system and analyze the dependence of quantum resources on temperature and magnetic field. The results indicate that the quantum resources of the nickel-radical molecular magnet persist even at room temperature. We show that while negativity (the entanglement measure) rapidly vanishes with increasing temperature and magnetic field, measurement-induced nonlocality and quantum coherence remain comparatively more stable and persist in regions where entanglement is absent. These results highlight the significance of nonclassical correlations beyond entanglement in thermally activated spin systems and suggest that such molecular magnets could serve as viable platforms for quantum information processing in realistic conditions.