In Spintronics we use both charges and spins to store, transmit and encode information. Magnetic information are non volatile and the addition of spin can also make some devices particularly efficient in terms of energy consumption. Potentialities are certainly high but concepts and technology cannot be trivially scaled below 10nm, a critical threshold that will be soon reached if the race of miniaturization will continue at the present rate. One technological issue is the fact that lithographic processes are expensive -or simply not convenient- as compared to bottom up approaches to fabricate devices with lateral dimensions below 10nm. There are, however, more fundamental problems to be faced below this (10nm-)threshold. Take for instance the spin injection/filtering mechanism that is at the basis of functioning of current spin valves (or spinFET) or the concepts of energy bands, bulk magnetization, spin accumulation at the interface, spin torque: these simply do not hold at the nano-scale and their ultimate limits need to be radically revised.
In the context of Quantum Computation, spin is an ideal quantum bit with a well defined algebra and for which quantum algorithms can be readily encoded. Yet, the physical implementation of scalable quantum gates with single spins was considered a dream so far due, for instance, to the difficulty in reading single spin with an electrical circuit and to the relatively short coherence time of an electronic spin embedded in solid state matrix. Clearly, these fields present huge difficulties and breakthroughs are needed to overcome the above-mentioned bottlenecks. Rather than an incremental evolution of conventional concepts and technologies, we start from recent achievements obtained in different fields (Molecular Magnetism, Molecular electronics, Supramolecular Chemistry, low-dimension carbon systems) to image a viable route for boosting a completely new field of research: Molecular Quantum Spintronics.
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