Date: Tuesday, Jun 2nd
Presenter: Paul L. McEuen, Professor of Physics, Cornell University
The electronic properties of carbon nanotubes exhibit fascinating parallels to phenomena normally encountered in elementary particle physics. The quantization of the electron motion around the circumference of the tube gives rise to electron-hole symmetric subbands. Each subband is analogous to a different elementary particle/antiparticle, and the mathematics describing this is analogous to early versions of string theory. Furthermore, the subbands have a relativistic dispersion relation, with the speed of light replaced by the Fermi velocity. Here we present three new results on nanotubes in the spirit of this analogy: (1) ultrafast measurements of the electron propagation velocity; (2) a new kind of topological spin-orbit effect that arises from the nanotube's cylindrical geometry, and (3) measurements of ultra-efficient electron-hole pair production by high energy carriers. These results are of fundamental interest, but they also have implications in areas as diverse as quantum computation and solar energy conversion.
Paul McEuen is a world expert on the science and technology of nanostructures. He is a pioneer of single molecule devices, scanning probe microscopy of nanostructures and applications of nanoelectronics in chemistry and biology.