Nanotechnology/Nanoelectronics

Navigate << Prev: Nano-optics >< Main: Nanotechnology >> Next: Nanomechanics __TOC__ Nanoelectronics Nanoelectronics is expected to be cheaper to fabricate than silicon / gallium / arsenic based electronics. It also might be small enough to not require a power source as it is possible to abstract a small amount of energy from the surrounding heat by a molecular level energy scavenging system S. Meininger et al., "Vibration-to-Electric Energy Conversion", IEEE Trans. VLSI Systems, 64-76 (2001). Diffusive and Ballistic Electron Transport Double barrier systems Coulomb Blockade Coulomb Blockade Tunnel Junctions Quantum Tunneling Moletronics / Molecular Electronics Using molecules for electronics, often called moletronics or molecular electronics Petty M.C., Bryce M.R. and Bloor D., An Introduction to Molecular Electronics, (Edward Arnold, London, 1995). , is a new technology which is still in its infancy, but also brings hope for truly atomic scale electronic systems in the future. One of the more promising applications of molecular electronics was proposed by the IBM researcher Ari Aviram and the theoretical chemist Mark Ratner in their 1974 and 1988 papers Molecules for Memory, Logic and Amplification, (see Unimolecular rectifier) A. Aviram and M. A. Ratner, “Molecular Rectifier” (Chemical Physics Letters 29: 277 (1974)). A. Aviram, J. Am. Chem. Soc., 110 5687-5692 (1988) . This is one of many possible ways in which a molecular level diode / transistor might be synthesized by organic chemistry. A model system was proposed with a spiro carbon structure giving a molecular diode about half a nanometre across which could be connected by polythiophene molecular wires. Theoretical calculations showed the design to be sound in principle and there is still hope that such a system can be made to work. However one researcher, experimentalist Jan Hendrik Schön, could not wait for the necessary technical progress and at a time when he was publishing one scientific paper a week and winning scholarships, heading for the top in nanotechnology, it was discovered he had fabricated both the experiment where such a device worked and several other potentially important milestones in the field. This incident is discussed by David Goodstein in Physics World . However it seems only a matter of time before something like this proposed elegant solution to the problem demonstrates the behavior of a diode. Quantum Computing A quantum computer would be incredibly fast compared to microelectronics. It would also be able to use the properties of quantum mechanics to be in fuzzy states which could represent many numbers at once allowing a massive density of memory. How such devices would be nano-fabricated is however way beyond current technology. The first working 2-qubit quantum computer was demonstrated in 1998. In 2006, the first working 12 qubit quantum computer was demonstrated. Bibliography Michel le Bellac, A Short Introduction to Quantum Information and Quantum Computation, Cambridge University Press (2006) . Michael A. Nielsen and Isaac L. Chuang, Quantum Computation and Quantum Information, Cambridge University Press (2000) . Resources on the net Keithley.com has some freely available handbooks on low noise measurements in electronics and nanotechnology Nanoelectronics Overview at Understandingnano References See also notes on editing this book about how to add references Nanotechnology/About#How_to_contribute.