Observing magnetic anisotropy in electronic transport through individual single-molecule magnets

TL;DR

This paper reviews methods for probing magnetic anisotropy in single-molecule magnets using electronic transport, highlighting gate spectroscopy's robustness and exploring excitations related to spin and vibrational modes.

Contribution

It introduces and compares various electron transport techniques, emphasizing gate spectroscopy for quantifying magnetic anisotropy in individual SMMs.

Findings

Gate spectroscopy effectively measures magnetic anisotropy.

Transport measurements reveal excited spin and vibrational states.

High-energy excitations are linked to spin multiplets and vibrational modes.

Abstract

We review different electron transport methods to probe the magnetic properties, such as the magnetic anisotropy, of an individual Fe4 SMM. The different approaches comprise first and higher order transport through the molecule. Gate spectroscopy, focusing on the charge degeneracy-point, is presented as a robust technique to quantify the longitudinal magnetic anisotropy of the SMM in different redox states. We provide statistics showing the robustness and reproducibility of the different methods. In addition, conductance measurements typically show high-energy excited states well beyond the ground spin multiplet of SMM. Some of these excitations have their origin in excited spin multiplets, others in vibrational modes of the molecule. The interplay between vibrations, charge and spin may yield a new approach for spin control.