Influence of multi-level impurities on the dynamics of ultrashort electromagnetic pulses in carbon nanotubesAlexander V. Zhukov, Roland Bouffanais, Natalia N. Konobeeva, Mikhail B. Belonenko and Thomas F. GeorgeEPL, 106 3 (2014) 37005DOI: https://doi.org/10.1209/0295-5075/106/37005