  New advances in single-atom manipulation are leading to the creation of
atomic structures on H passivated Si surfaces with functionalities important
for the development of atomic and molecular based technologies. We perform
total-energy and electron-transport calculations to reveal the properties and
understand the features of atomic wires crafted by H removal from the surface.
The presence of dopants radically change the wire properties. Our calculations
show that dopants have a tendency to approach the dangling-bond wires, and in
these conditions, transport is enhanced and spin selective. These results have
important implications in the development of atomic-scale spintronics showing
that boron, and to a lesser extent phosphorous, convert the wires in
high-quality spin filters.
