title: Ultrafast relaxation dynamics via acoustic phonons in carbon nanotubes.
abstract: Carbon nanotubes as one-dimensional nanostructures are ideal model systems to study relaxation channels of excited charged carriers. The understanding of the ultrafast scattering processes is the key for exploiting the huge application potential that nanotubes offer, e.g., for light-emitting and detecting nanoscale electronic devices. In a joint study of two-color pump-probe experiments and microscopic calculations based on the density matrix formalism, we extract, both experimentally and theoretically, a picosecond carrier relaxation dynamics, and ascribe it to the intraband scattering of excited carriers with acoustic phonons. The calculated picosecond relaxation times show a decrease for smaller tube diameters. The best agreement between experiment and theory is obtained for the (8,7) nanotubes with the largest investigated diameter and chiral angle for which the applied zone-folded tight-binding wave functions are a good approximation.
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin, Germany. olga.dyatlova@tu-berlin.de
authors.forename: Olga A
authors.initials: OA
authors.lastname: Dyatlova
authors.forename: Christopher
authors.initials: C
authors.lastname: Köhler
authors.forename: Ermin
authors.initials: E
authors.lastname: Malic
authors.forename: Jordi
authors.initials: J
authors.lastname: Gomis-Bresco
authors.forename: Janina
authors.initials: J
authors.lastname: Maultzsch
authors.forename: Andrey
authors.initials: A
authors.lastname: Tsagan-Mandzhiev
authors.forename: Tobias
authors.initials: T
authors.lastname: Watermann
authors.forename: Andreas
authors.initials: A
authors.lastname: Knorr
authors.forename: Ulrike
authors.initials: U
authors.lastname: Woggon