# Vibron-assisted spin excitation in a magnetically anisotropic nickelocene complex

## TL;DR

This study demonstrates vibron-assisted spin excitations in a nickelocene-based molecule using STM, revealing new pathways for electrically controlling molecular magnetism through spin-vibration interactions.

## Contribution

It reports the first observation of vibron-assisted spin excitations in a single magnetic molecule and explains the phenomenon with first-principles calculations, advancing molecular spintronics.

## Key findings

- Vibron-assisted spin excitation occurs at higher energy than usual spin excitations.
- Spin excitations can be quenched by modifying molecule-metal coupling.
- First-principles calculations support the experimental observations.

## Abstract

The ability to electrically-drive spin excitations in molecules with magnetic anisotropy is key for high-density storage and quantum-information technology. Electrons, however, also tunnel via the vibrational excitations unique to a molecule. The interplay of spin and vibrational excitations offers novel routes to study and, ultimately, electrically manipulate molecular magnetism. Here we use a scanning tunneling microscope to electrically induce spin and vibrational excitations in a single molecule consisting of a nickelocene magnetically coupled to a Ni atom. We evidence a vibron-assisted spin excitation at an energy one order of magnitude higher compared to the usual spin excitations of nickelocene and explain it using first-principles calculations that include electron correlations. Furthermore, we observe that spin excitations can be quenched by modifying the Ni-nickelocene coupling. Our study suggests that nickelocene-based complexes constitute a model playground for exploring the interaction of spin and vibrations in the electron transport through single magnetic molecules.