Prospects and challenges for quantum information processing using carbon nanotubes
Seminar Room 1, Newton Institute
This talk will review experimental progress toward the use of carbon nanotubes as a basis for solid-state quantum information processing. This topic is in its infancy, to say the least, but some modest accomplishments can be presented. These include local gate control of conductance and tunneling, the formation of multiple quantum dots, and demonstrated signatures of spin physics, including the Kondo effect.
The motivation to use nanotubes in this way is that these systems have very weak spin orbit coupling, mostly zero nuclear spin, and confined phonon spectra. One difficulty, of course, is that nanotubes are one dimensional. While schemes for universal quantum computing with nearest-neighbor-only coupling in one dimension are known, these appear to require unrealistic precision in control of exchange coupling. We expect that by the time control of nanotube spin and charge are sufficiently under control to provide precise qubit control, comparable advancements toward encorporating nanotubes into higher-dimensional structures will have also developed. For now, we concentrating on precise control of exchange and tunnel coupling in one dimension.