Physical Review Letters
Print Issue of 3 June 2002

Phys. Rev. Lett. 88, 226401 (2002)


Photoinduced Quantum Interference Antiresonances in pi -Conjugated Polymers

R. Österbacka,1 X. M. Jiang,2 C. P. An,2 B. Horovitz,3 and Z. V. Vardeny2
1Department of Physics, Åbo Akademi University, Porthansgatan 3, FIN-20500 Turku, Finland
2Department of Physics, University of Utah, 114 South 1400 East, Salt Lake City, Utah 84112-0830
3Department of Physics, Ben Gurion University of the Negev, Beer-Sheva 84105, Israel

(Received 19 June 2001; published 15 May 2002)

We observed photoinduced quantum interference antiresonances between several discrete infrared-active vibrations and the lower-polaron continuous absorption band in a series of pi -conjugated polymer films having superior planar orders, where the polaron transition energy is relatively small. The photoinduced Fano-type antiresonances are well explained by extending the amplitude mode model beyond the adiabatic limit. The agreement between the data and the model confirms the presence of a continuous electronic band above the polaron state. We show that high frequency modes are strongly coupled to electrons, with implications for superconductivity. ©2002 The American Physical Society


PACS: 71.38.-k, 63.22.+m, 78.30.Jw       

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