Quantum-dot cellular automata using buried dopants

Abstract

The use of buried dopants to construct quantum-dot cellular automata is investigated as an alternative to conventional electronic devices for information transport and elementary computation. This provides a limit in terms of miniaturization for this type of system as each potential well is formed by a single dopant atom. As an example, phosphorous donors in silicon are found to have good energy level separation with incoherent switching times of the order of microseconds. However, we also illustrate the possibility of ultrafast quantum coherent switching via adiabatic evolution. The switching speeds are numerically calculated and found to be tens of picoseconds or less for a single cell. Th..