Fabrication of a regular array of atomic silicon wires on silicon

We report on the experimental realization of atomically straight, single wires of Si atoms on a Si surface. The Si wires were formed by solid-source molecular beam epitaxy (MBE) on a specific substrate prepared by a thermal treatment of a vicinal Si(111) wafer. The structures of the substrate and the atomic wire were investigated by scanning tunneling microscopy (STM). The substrate consists of an array of atomically straight step edges with a uniform structure serendipitously suitable for self-assembly of the atomic wires. The isotopic version of this structure - single lines of ²⁹Si on ²⁸Si- is expected to be the most basic building block for the all-silicon quantum computer [1], which utilizes the nuclear spins of individual Si isotopes as quantum bits (qubits).