Single-electron charge qubit in a double quantum dot

Abstract

A semiconductor double quantum dot provides a simple artificial two-level system (qubit) that can be manipulated by electronic signals. Full one-qubit operation is demonstrated with a high-speed voltage pulse. In addition, strength of decoherence can be controlled to allow efficient initialization of the qubit. Remaining uncontrolled decoherence is discussed with background charge fluctuations, cotunneling, and electron-phonon coupling. Moreover, charge detection of a double dot is demonstrated with a quantum-point-contact charge detector. © 2006 Springer Science+Business Media, Inc.