Interaction of spin and vibrations in transport through single molecule magnets.

Measurement of transport in nanoscale magentic systems show how a few magnetic atoms in such environment respond to electron current. The environment is provided by ligand groups that hold atoms together in a single molecule held in the middle of a break junction. These systems are refered as single molecule magnets, which are consituted by large spinmoment with spin anisotropy.

 Illustration of a molecular junction.

The tunel effect that gives several charge states of the single molecule magnet can exhibit enhanced magnetic properties. When such charge states are only virtually accessible, effective spin–spin exchange interaction arises and inelastic excitation of the spin moment is possible, allowing for time-dependent control.

The longitudinal coupling to the vibration increases the zero field splitting and suppresses the quantum spin tunneling. A vibrationally induced quantum spin tunneling effect can occur at zero bias if transverse coupling is present as well. The transition to virtual vibrational excited states and the transverse spin mixing in these virtual states results in a Kondo effect. The Kondo effect describes the scattering of electrons creating a conductance path in metals due to magnetic impurities. 

Fuente: May F. et al. (2011). Interaction of spin and vibrations in transport through single-molecule magnets. Recuperado el 11 de mayo de 2013, de http://www.beilstein-journals.org/bjnano/content/pdf/2190-4286-2-75.pdf