Observation of excitonic n-strings in a quasi-one-dimensional charge-transfer crystal

N. Peyghambarian, K. Meissner, B. Fluegel, S. Mazumdar, Fangyeong Guo, M. Kuwata-Gonokami, Y. Sato, K. Ema, R. Shimano, T. Tokihiro, H. Ezaki, E. Hanamura

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Collective excitations, such as plasmons, rotons, electron-hole liquid, and excitonic molecules, have been extensively studied in condensed matter. Wannier excitons in inorganic semiconductors are bound by the exchange interactions between two electrons of the exciton, and the bound state of more than two excitons is not possible. We demonstrate here a new type of collective excitations, bound states of multiple charge-transfer (CT) excitons. Coulomb interactions in one dimension are shown to bind a train of several (more than two) CT excitons. Experimental evidence for these new type of elementary excitations is reported in a quasi-one-dimensional CT crystal of anthracene PMDA. High density excitation by femtosecond light pulses generates multi-exciton chains, which we refer to as excitonic n-strings with n = 1, 2, 3, etc., along the stack axis of the crystal. Both the n = 2 excitonic string (biexciton) and the n = 3 string (tri-exciton) are observed. This report provides evidence for an n>2 exciton chain in this system. The stability of the n-string exciton is supported by our theoretical calculations based on the extended Hubbard Hamiltonian in one dimension.

Original languageEnglish
Title of host publicationElectrical, Optical, and Magnetic Properties of Organic Solid State Materials
EditorsAnthony F. Garito, Alex K-Y. Jen, Charles Y-C. Lee, Larry R. Dalton
PublisherPubl by Materials Research Society
Number of pages6
ISBN (Print)1558992278
Publication statusPublished - 1994 Jan 1
EventProceedings of the MRS 1993 Fall Meeting - Boston, MA, USA
Duration: 1993 Nov 291993 Dec 3

Publication series

NameMaterials Research Society Symposium Proceedings
ISSN (Print)0272-9172


OtherProceedings of the MRS 1993 Fall Meeting
CityBoston, MA, USA

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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