A. Nagarajan, S. Mukherjee, et al.
Journal of Applied Mechanics, Transactions ASME
We have investigated excitons in highly aligned single-walled carbon nanotubes (SWCNTs) through optical spectroscopy at low temperatures down to 1.5 K and high magnetic fields (B) up to 55 T. SWCNT/polyacrylic acid films were stretched, giving SWCNTs that are highly aligned along the direction of stretch (n). Utilizing two well-defined measurement geometries, n B and n B, we provide unambiguous evidence that the photoluminescence energy and intensity are only sensitive to the B -component parallel to the tube axis. A theoretical model of one-dimensional magnetoexcitons, based on exchange-split "bright" and "dark" exciton bands with Aharonov-Bohm-phase-dependent energies, masses, and oscillator strengths, successfully reproduces our observations and allows determination of the splitting between the two bands as ∼4.8 meV for (6,5) SWCNTs. © 2008 The American Physical Society.
A. Nagarajan, S. Mukherjee, et al.
Journal of Applied Mechanics, Transactions ASME
Ronald Troutman
Synthetic Metals
O.F. Schirmer, W. Berlinger, et al.
Solid State Communications
John G. Long, Peter C. Searson, et al.
JES