Quantitative measurement of the magnetic exchange interaction across a vacuum gap

Phys Rev Lett. 2011 Jun 24;106(25):257202. doi: 10.1103/PhysRevLett.106.257202. Epub 2011 Jun 24.


We demonstrate that magnetic exchange force spectroscopy allows for a quantitative determination of the distance-dependent magnetic exchange interaction across a vacuum gap. Experiments were performed on the antiferromagnetic Fe monolayer on W(001) with magnetically sensitive tips and compared to first-principles calculations performed for different cluster tip models. For stable tips, which can be distinguished from unstable tips by analyzing the dissipation signal, very good agreement with theory is observed.