PHYSICS:
Manipulating Magnetism in a Single Molecule
Michael F. Crommie
One of the key questions facing researchers studying molecular electronic devices is what happens when molecules come in contact with metals. A subtle effect known as the Kondo resonance offers one way to study these contacts. In his Perspective, Crommie discusses results reported in the same issue by Zhao et al. on the Kondo effect in a single molecule on a gold surface. Normally a cobalt phthalocyanine molecule sits flat on the metal surface, but when hydrogen atoms are pruned off with a scanning tunneling microscope tip, the molecule arches away from the surface. This causes the spins of the electrons in the metal to interact with the spin of the cobalt atom to form a Kondo resonance. The result opens the way for fundamental studies of spin behavior in molecules that may influence future molecular device applications.
The author is in the Physics Department, University of California, Berkeley, CA 94720, USA, and the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. E-mail: crommie{at}berkeley.edu