Direct access to the quantum dynamics of molecular nanomagnets.

The study, published in the important scientific journal Nature Physics, was coordinated by scientists of the new Department of Physics and Earth Sciences in the framework of an international collaboration involving theoretical and experimental physicists, as well as chemists.

Magnetic nanostructures (with dimensions of the order of one billionth of meter) are fundamental building blocks in emerging technologies such as spintronics and quantum computation. With respect to a typical magnetic material, the tiny size of these systems leads to phenomena characteristic of quantum mechanics, which can be exploited in the design of powerful computation algorithms and devices.

A crucial aspect in this field is the comprehension of the dynamics, i.e., the way the state of electrons behind magnetism evolves in the course of time. Since these dynamics have very small characteristic time- and length-scales (of the order of one thousandth of nanosecond and fractions of nanometer, respectively), their direct determination had been impossible so far.

The work “Spin dynamics of molecular nanomagnets unravelled at atomic scale by four-dimensional inelastic neutron scattering ”, just published in the prestigious journal Nature Physics is the result of an international collaboration in which a group of researcher of the Department of Physics and Earth Sciences had a leading role. The article illustrates a new approach to directly determine the spin dynamics at atomic scale by exploiting cutting-edge neutron scattering measurements. The effectiveness of this method has been demonstrated by investigating a ring with eight Chromium atoms.

This is one of the most studied molecular nanomagnets for the strongly quantum character of its dynamics. This result opens remarkable perspectives of fundamental and technological character, for the potential applications of molecular ring as fundamental units (qubits) in quantum computers.

Bibliographical reference: Michael L. Baker, Tatiana Guidi, Stefano Carretta, Jacques Ollivier, Hannu Mutka, Hans U. Güdel, Grigore A. Timco, Eric J. L. McInnes, Giuseppe Amoretti, Richard E. P. Winpenny & Paolo Santini, Nature Physics Published online: 30 September 2012 doi:10.1038/nphys2431 (

http://www.nature.com/nphys/journal/vaop/ncurrent/abs/nphys2431.html).