Family effects on excitons in semiconducting carbon nanotubes

Abstract

Family behavior of excitons is studied in carbon nanotubes based on a k.p scheme. Effects responsible for family pattern are characterized by two parameters β representing higher-order terms in the effective Hamiltonian responsible for trigonal warping and p representing amount of effective flux due to curvature and lattice distortion. These parameters are determined through comparison with empirical formula of the lowest exciton and experiments of two-photon absorption giving excited exciton states. The observed family pattern can be reproduced much better for the first gap than for the second gap. © 2009 The Physical Society of Japan.