Self-aligned Side Gates for Nanowires and Nanotubes: the Development and Application of a New Gate Architecture for Manipulating and Defining 1d Quantum Dots with Possibilities for Quantum Computation

The book presents the experimental and theoretical development of a simple to fabricate new control architecture for nanotubes and nanowires. The architectures arrangement offers new possibilities for electrical, magnetic and mechanical control and a new spin detection architecture with applicability to quantum computation is presented. The fabrication procedure allows twin side gate electrodes to be placed within 5nm of a nanotube. The nanotube is suspended between the twin gate electrodes and the suspension creates an air gap between the nanotube and the gates. The air gap can help when applying high fields and should reduce noise, shielding and hysteretic effects. The twin gate structure allows for high field gradients which can be used to modify band gaps, while the proximity and dimensions assist the formation of well-defined tunnel barriers. Ultimately it is hoped that the architecture will aid the creation and control of quantum dots and offer the possibility of extending low dimensional experiments in GaAs to nanotubes and nanowires.