A Single Atom Magnet
Magnets possess both strength and memory. These two properties make them useful for a broad variety of applications, which involve action at a distance or retention of magnetic information. The miniaturization of magnets, like that of transistors, cannot go on indefinitely. As a magnet is reduced in size, thermal fluctuations overcome the anisotropy barrier that keeps the magnetic axis stable, leading to the loss of permanent magnetization.
A recent study, carried out jointly by a team of researchers led by Pietro Gambardella (ETH Zürich) and external pageHarald Brunecall_made (EPF Lausanne), may have reached the bottom of this quest. Their work, recently published in external pageSciencecall_made, shows that single Holmium atoms deposited on a nonmagnetic MgO substrate display high coercivity and magnetic remanence up to a temperature of about 40 K, on a timescale of one hour.
- Single Atom Magnets
- Magnetic remanence in single atoms, F. Donati, S. Rusponi, S. Stepanow, C. Wäckerlin, A. Singha, L. Persichetti, R. Baltic, K. Diller, F. Patthey, E. Fernandes, J. Dreiser, Ž. Šljivančanin, K. Kummer, C. Nistor, P. Gambardella and H. Brune, Science, 352, 318 (2016). external pagearticlecall_made external pagesupplementary informationcall_made