event
Friday 17 Feb 2012: Colloquium: High Magnetic field studies of Graphene
Prof. Robin Nicholas - The University of Oxford
Newman F 12:00-13:00
From its discovery in 2004 to a Nobel Prize in 2010 for Novosolev and Geim, the rise of graphene has been nothing short of spectacular, and it is revolutionizing a wide range of science and technology. Graphene is a metal with controllable densities of electrons and holes both of which act like massless charged particles moving relativistically. Using very high high magnetic fields (160T) we can probe the relativistic dispersion of graphene and graphite, showing how mass can be re-introduced through interlayer tunnelling. At low temperatures graphene shows a particularly strong quantized Hall effect due to the high Dirac velocity combined with very strong electron lattice coupling.
Rolling the graphene up into carbon nanotubes turns the tubes into semiconductors which also show dramatic properties in high magnetic fields, including direct observation of the Aharanov-Bohm effect. We demonstrate this by making measurements on individual nanotubes where the linewiths can be up to 100 times narrower than for the typical ensembles studied previously.
