Quantum transport through single molecules
UA find may lead to pin-sized computers,
by Paul Allen (Tucson Citizen, September 28, 2006)
New tech for old transistor,
by T.V. Jayan (The Telegraph, Calcutta, India, September 18, 2006)
Quantum effect offers molecular
transistors, by Justin Mullins (New Scientist, September 8, 2006)
UA Physicists Invent 'QuIET'
Single Molecule Transistors, by Lori Stiles (UA News, August 30, 2006)
Honey, I Shrunk the PC,
by Mark Anderson (Wired, June 9, 2005)
New look for molecular transistors,
by Dr. Isabelle Dumé (PhysicsWeb, March 31, 2005)
We propose
a new type of molecular transistor, the
Quantum Interference Effect Transistor (QuIET), based on tunable current suppression due
to quantum interference. We show that any aromatic hydrocarbon ring has
two-lead configurations for which current at small voltages is suppressed
by destructive interference. A transistor can be created by providing
decoherence or elastic scattering at a site
on the ring. We propose several molecules which could tunably
introduce the necessary scattering, as well as a proof of principle using a
scanning tunneling microscope tip. Within the
self-consistent Hartree-Fock approximation, the QuIET is shown to have
characteristics strikingly similar to those of conventional field effect and
bipolar junction transistors.
Metal nanowires
UA Physicists Find Key to Long-Lived Metal Nanowires,
by Lori Stiles (UA News, August 24, 2005)
Microscopic contacts which form spontaneously between two pieces of metal which touch have been shown to exhibit conductance quantization under a wide variety of conditions. Recently, it has been shown that the mechanical properties of such metallic "nanowires" also exhibit interesting quantum-size effects, which are correlated with their electrical properties. In order to describe electrical and mechanical properties of nanoscopic metallic systems within a single theoretical framework, we have developed a scattering approach to nanomechanics. A simple picture of metallic nanocohesion in which conductance channels act as delocalized chemical bonds is derived in the jellium approximation. Universal mesoscopic oscillations of the cohesive force of order 1nN are predicted when a metallic quantum wire is stretched to the breaking point, which are synchronized with quantized jumps in the conductance. These predictions are in quantitative agreement with the pioneering experiment of Rubio, Agrait, and Vieira, who measured simultaneously the force and conductance during the formation and rupture of an atomic-scale gold nanowire.
Significant advances in the theory of metallic nanocohesion were made by applying techniques from quantum chaos.
Find out about the remarkable stability of metal nanowires.
Movies of quantum necking in stressed nanowires.
