Single atom metallic wires of arbitrary length are of immense scientific and technological interest. Much of the novel and exotic physics expected of one-dimensional electronic systems is described in great details by theory, but is still lacking thorough experimental verification and characterization. Electrons confined to one dimension are expected to develop remarkable properties such as Peierls transitions, collective spin and charge modes and Tomonaga Luttinger Liquid behaviour. Understanding 1D electrons also has technological implications owing to the drastic downscaling of devices and interconnects.
We are developing a promising alternative to step edges and vicinal surface templating commonly used to self assemble nanowires. We are taking advantage of Bi nanolines and a striking Si reconstruction forming on clean Si(001) surfaces when exposed to low doses of bismuth. This so-called Haiku stripe offers a number of exceptional features, not least an intriguing 1D electronic state extending along the centre of the Haiku core and the prospect of self assembling a novel category of subsurface atomic chains on Si(001) to explore transport in a truly isolated and one-dimensional wire.
An open challenge we did so far not manage to solve is connecting these nanowires to external leads to do transport measurements. Until we have a good idea, this project is put on hold.