Abstract
The continuum electron-phonon system is studied for -type polymers with an average charge of per site. For spontaneous bond dimerization and soliton excitations are possible if , where is the intrinsic gap and is the spontaneous dimerization gap when . Recently observed neutral-to-ionic transitions in mixedstack organic compounds are reinterpreted as the onset of such bond dimerization. For spontaneous order and a soliton lattice are found even if . The electronic gap then has a maximum at a finite .
- Received 9 March 1983
DOI:https://doi.org/10.1103/PhysRevLett.50.1942
©1983 American Physical Society