PROGRESS BEYOND THE STATE-OF-THE-ARTAs pointed out before, only the initial steps in organic spintronics have been undertaken. To reach the final goal in this sub-area (i.e., to design cheaper spintronic devices compatible with plastic technology), a long way needs to be pursued that involves a strong coordinative effort of the spintronics community with the two molecular communities in three major topics: i) The engineering of interfaces that allow tuning of the spin injection from the ferromagnetic electrode to the molecular spin collecting layer; ii) A better understanding of spin-dependent transport phenomena through molecular systems; iii) The design of new types of spintronic devices taking advantage of the multifunctional properties of molecular systems.
As far as the single-molecule nanospintronics is concerned, the progress beyond the state-of-the-art will take advantage of the possibility to tailor and manipulate molecules down to the single spin. Currently, this sub-area is strongly hindered by the reproducibility of the devices and by the chemical unstability of the magnetic molecules when they are in contact with the metallic electrodes. Still, the advances made in organic spintronics in relation with the hybrid interfaces formed by molecules organized on inorganic surfaces can serve as starting point to improve the stability of these nanodevices and to study the properties of these molecules individually. On the other hand, the addressing and readout of a single spin in these devices is another challenge that has been proposed theoretically but that needs to be demonstrated experimentally. In particular, scale reduction of the spintronic device down to a single molecule remains an open challenge. Finally, the use of magnetic molecules as spin qubits should allow for the development of quantum devices based on these units. However, this is a long term challenge. In the short term, the next steps will focus on increasing the coherence times of these molecules and integrating these qubits in scalable architectures by exploiting the ability of molecules to self-assemble.