Molecular Spin Electronics

This project aims to develop the core nanotechnology for novel molecular spin electronics based on controlled self-organisation of endohedral fullerenes. The ambitious long term goal is the experimental realization of a spin quantum computer. This necessitates a transdisciplinary approach involving physics, chemistry, micro- and nano technology. Our concept for a spin quantum computer architecture based on endohedral fullerenes (Fig. 1) is now internationally recognized. For the experimental realization of this concept, however, a major development effort has to be made, especially concerning the nanotechnology of supramolecular self organisation.

Fig. 1. Scheme for a solid-state spin quantum computer based on linear chains of endohedral fullerenes. The qubit is encoded in the electron-nuclear spin system of a paramagnetic atom trapped in a fullerene (this complex is called an "endohedral fullerene"). Qubit coupling is achieved by magnetic dipolar interaction between adjacent endohedral electron spins. The addressing gate is a pair of micro-fabricated wires that produce a magnetic field gradient along the linear fullerene chain. Universal quantum gates are realized by magnetic resonance pulses (not part of this project). The single-spin read-out gate is symbolic and will be developed elsewhere. Here, we aim to construct the endohedral fullerene quantum register using a combined physico-chemical nano-technology approach.

The main focus of the present project is therefore to develop this necessary nanotechnology. Some of the methods to be employed here have been demonstrated by other groups but they have to be adapted to the present case of fullerenes. Standing and future collaborations will be used in order to concentrate and import key know-how. To develop the nanotechnology of macro-molecular self-organisation has a broader significance than for the special application of a quantum computer. We expect that spin-off applications will develop, e.g. for organic solar cells and for magnetic sensors.