Atomically perfect bismuth wires
K. Miki(a), J.H.G. Owen(b), D.R. Bowler(b),
G.A.D. Briggs*(b), and K. Sakamoto(a)
(a)Electrotechnical Laboratory
Tsukuba, Ibaraki 305, Japan
(b)Materials
Department
Oxford University
Parks Road, Oxford OX1 3PH, UK |
This is an abstract
for a talk to be given at the
Fifth
Foresight Conference on Molecular Nanotechnology.
There will be a link from here to the full article when it is
available on the web.
A perfect quantum wire would have truly one-dimensional
electronic properties, and would open many possibilities for
advanced high performance electronic devices. A crucial factor in
the performance is the straightness of the wire; both roughness
and compositional imperfections degrade the quantum conductance
by inducing localization of electrons. We have discovered a way
to use nonequilibrium aspects of desorption processes to
fabricate atomically perfect wires of bismuth atoms in a Si(001)
surface. The wires can be made either by first covering a Si(001)
surface with a monolayer or so of Bi and then heating it until
most of the bismuth desorbs, or by depositing Bi on a Si(001)
surface at a temperature at which the desorption rate is close to
the incident flux. Because of the inherent stability of the
wires, the temperature for Bi desorption from them is higher than
from the surface as a whole. We can observe the formation of
these wires by making atomic movies in an elevated temperature
scanning tunneling microscope. The wires are 1 nm wide, hundreds
of nm long, and absolutely straight. They are atomically perfect:
there are no kinks or missing dimers in any of the wires.
*Corresponding Address:
Andrew Briggs, Department of Materials, Parks Road, Oxford OX1
3PH, England, ph: +44-1865-273725 or +44-1865-558007h, fax:
+44-1865-273783, email: [email protected]
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