These findings were in the the front cover highlights of the journal Nature Materials (“The classical and quantum dynamics of molecular spins on graphene”, DOI: 10.1038/nmat4490)
“Graphene is a bi-dimensional material made up of carbon atoms in an hexagonal lattice and has exceptional chemical and physical properties making it very interesting for a number of potential applications such as photo-voltaic cells, transistor, integrated circuits, etc. - explains Rettori, associate professor of Condensed Matter Physics - and it is an ideal system for the development of spintronics, the evolution of electronics that exploits spin, the intrinsic magnetic momentum of the electron.”
“To design nanodevices based on spintronics of surface layers and electric manipulation of spins - continues the academic - it is fundamental to deposit on graphene, molecules or atoms endowed with their own spin and study the quantum dynamics.”One of the project currently at study is that of creating spintronic nanodevices the characteristics of which are determined by the quantum properties of a few single molecule magnets (SMMs), grafted onto the graphene.
“The advantage of an SMM, with dimensions in the nanometer range (one-billionth of a metre) - explains Rettori - is that at low temperatures it is able to maintain its magnetic spin for a very long time and, through some chemical engineering techniques, it is possible to use it in various ways, such as coupling it to a suitable substrate like graphene”.Rettori has developed the theoretical analysis of the problem, as part of a team made up of researchers from universities and research institutes in Germany, Spain and Italy.
“We were able to "attach" to graphene single magnetic molecules of Fe4 (a molecule with a magnetic nucleus of 4 ions of Iron) - reports Rettori. - We have thus created a 'hybrid' system in which the static properties remain unaltered compared to what has been observed in a 3D crystal formed by such molecules, but in which quantum dynamics can be profoundly modulated as a consequence of the peculiar electronic properties of graphene, whose electrons form a bi-dimensional gas of relativistic particles.”
“In this 'hybrid' system, at low temperature, the relaxation time of magnetism is a million times lower than that of a molecular magnetic crystal. This happens because the interaction among the electrons of the molecule and those of graphene activates a fully coherent, resonant quantum tunnel mechanism, a regimen that has never been observed before.”
“Our study - concludes Rettori - can contribute to the realisation of spintronic nanodevices based on graphene”.