Where nanotechnology meets quantum computation

Since the invention of the scanning tunnelling microscope (STM) in the early 1980s atomic level microscopy has taken on a new dimension. The STM and the atomic force microscope (AFM) have become key instruments in the study of phenomena in the smallest dimensions ranging from magnetism in ultra-thin films, through the understanding of how atoms and molecules organise themselves, to insights into the propagation of electron waves. A good understanding of these issues will facilitate the manufacture of components or devices that are a few atomic dimensions in size and this will have far-reaching implications in fields ranging from medicine through to consumer electronics. As early as the 1970s, the scientific community was discussing the possibility of embedding a few molecules, or even a single molecule, between electrodes to perform the basic switching function. This is now possible in the case of individual components but key challenges lie with the economic commercial fabrication of whole devices. A key challenge lies in determining whether such quantum computers will work and how quantum effects can be used to perform variety of previously unsuspected and potentially useful schemes of information processing