Authors: L. Livadaru, J.L. Pitters, M. Taucer, R.A. Wolkow
Affilation: University of Alberta / NINT, Canada
Pages: 35 - 37
Keywords: coherent electron dynamics, computing architectures, charge manipulation and control
A dangling bond (DB) on a silicon surface atomic has been found to behave as an atomic-scale quantum dot [1-4]. This opens up the possibility of using DBs as building blocks for novel electronic structures, pushing the ultimate limits of nanoscale devices. Examples include: artificial molecules, nanowires, and alternate computing architectures such as the Quantum-Dot Cellular Automata (QCA). We study theoretically various aspects of DB structures on an H-terminated 2x1 Si(001) surface, which are of primary interest for the advancement of any device architecture: (i) The “diatomic” artificial DB molecule, composed of two tunnel-coupled DBs; its coherence and polarization properties in different ionic states; its potential as a charge qubit. (ii) Signal propagation along a QCA wire for various architectures and as a function of temperature. (iii) The interaction of such DB structures with external control electrodes and manipulators, including the interaction with a scanning tunneling microscopy (STM) probe. In the latter case our model helps to bring a better understanding of the non-trivial STM imaging process of isolated or tunnel-coupled DBs.