Puzzling results explained: a multiband approach to Coulomb drag and indirect excitons

Inleiding: Mystifying results in excitonic Coulomb drag experiments obtained independently by two research groups in the USA explained by the CMT group (M. Zarenia, D. Neilson and F. Peeters) in a recent Physical Review Letters paper. Taking a multiband approach explains 'electron-hole reverse drag' and exciton formation Mystifying experimental results obtained independently by two research groups in the USA seemed to show coupled holes and electrons moving in the opposite direction to theory. Now, a new theoretical study has explained the previously mysterious result, by showing that this apparently contradictory phenomenon is associated with the bandgap in dual-layer graphene structures, a bandgap which is very much smaller than in conventional semiconductors. The study authors, which included Mohammad Zarenia , David Neilson and Francois Peeters at the University of Antwerp, Condensed Matter Theory group, and Alex Hamilton at the University of New South Wales, found that the new multiband theory fully explained the previously inexplicable experimental results. Exciton transport Exciton transport offers great promise to researchers, including the potential for ultra-low dissipation future electronics. An exciton is a composite particle: an electron and a 'hole' (a positively charged 'quasiparticle' caused by the absence of an electron) bound together by their opposite electrical charges.