Tunneling Spectra of Individual Magnetic Endofullerene Molecules

TL;DR

This paper demonstrates the electrical contact and spin excitation measurement of individual magnetic N@C60 molecules, advancing techniques for single-molecule spin control relevant for quantum information and data storage.

Contribution

It reports the first measurement of spin excitations in single magnetic endofullerene molecules via tunneling spectra, confirming their magnetic properties and theoretical modeling.

Findings

Successful electrical contact to individual N@C60 molecules

Observation of spin state transitions with magnetic field

Theoretical reproduction of tunneling spectra considering exchange interactions

Abstract

The manipulation of single magnetic molecules may enable new strategies for high-density information storage and quantum-state control. However, progress in these areas depends on developing techniques for addressing individual molecules and controlling their spin. Here we report success in making electrical contact to individual magnetic N@C60 molecules and measuring spin excitations in their electron tunneling spectra. We verify that the molecules remain magnetic by observing a transition as a function of magnetic field which changes the spin quantum number and also the existence of nonequilibrium tunneling originating from low-energy excited states. From the tunneling spectra, we identify the charge and spin states of the molecule. The measured spectra can be reproduced theoretically by accounting for the exchange interaction between the nitrogen spin and electron(s) on the C60 cage.