Observation of breather excitons and soliton in a substituted polythiophene with a degenerate ground state

Takayoshi Kobayashi,1,2,3,4 Juan Du,1,2 Wei Feng,5 Katsumi Yoshino,6 Sergei Tretiak,7 Avadh Saxena,7 and Alan R. Bishop7 1Department of Applied Physics and Chemistry and Institute for Laser Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan 2JST, ICORP, Ultrashort Pulse Laser Project, , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan 3Department of Electrophysics, National Chiao Tung University, 1001 Ta Hsueh Road, Hsin-Chu 3005, Taiwan 4Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871, Japan 5School of Materials Science and Engineering, Tianjin University, Tianjin 300072, People’s Republic of China 6Shimane Institute for Industrial Technology, 1 Hokuryo-cho, Matsue, Shimane 690-0816, Japan 7Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA Received 25 October 2009; revised manuscript received 22 December 2009; published 5 February 2010