Probing molecular spin clusters by local measurements

TL;DR

This paper investigates how local measurements can effectively estimate parameters in molecular nanomagnets' spin Hamiltonians, demonstrating their precision in characterizing quantum magnetic properties.

Contribution

It introduces a quantum estimation framework for molecular nanomagnets and shows local measurements can accurately determine key physical parameters.

Findings

Local measurements enable precise parameter estimation.

Quantum Fisher information quantifies measurement effectiveness.

Local measurements are effective even on parts of the molecule.

Abstract

We address the characterization of molecular nanomagnets at the quantum level and analyze the performance of local measurements in estimating the physical parameters in their spin Hamiltonians. To this aim, we compute key quantities in quantum estimation theory, such as the classical and the quantum Fisher information, in the prototypical case of an heterometallic antiferromagnetic ring. We show that local measurements, performed only on a portion of the molecule, allow a precise estimate of the parameters related to both magnetic defects and avoided level crossings.