Using the master equation approach, we look for fingerprints of the interaction between the localized spin $S$ of a nanomagnet coupled to spin-polarized leads and its quantized vibrational modes. We find that the stationary and transient currents are sensitive to vibron-assisted transitions of the molecular spin on both sides of the anisotropy barrier. Such transitions are associated with vibron-dressed states and triggered under resonant conditions. Transport calculations are presented for two antiparallel configurations of the spin-polarized electrodes. In the first configuration, and far from a resonance point, a blockade is imposed on both the electronic and molecular spins via their exchange interaction. When sweeping the magnetic field through resonance, the spin-vibron interaction removes this blockade and allows the indirect reading of resonant transitions as the molecular spin climbs the left side of the anisotropy barrier. In the second configuration, the anisotropy barrier is overcome but the vibron-assisted transitions on the right side of the anisotropy barrier “delocalize” the molecular spin and do not allow the complete current-induced magnetic switching $-S\to S$. In both configurations, the stationary current increases on resonance, due to additional transport channels triggered by the spin-vibron coupling. Therefore, the switching of the spin-vibron coupling could be detected in future transport experiments.

• Received 3 March 2023
• Revised 30 June 2023
• Accepted 10 July 2023

DOI:https://doi.org/10.1103/PhysRevB.108.024416