Abstract
Solitons in a one-dimensional charge-density-wave system with half-filled electron bands are studied theoretically with a continuum model. This model is a continuum version of the one of polyacetylene recently considered by Su, Schrieffer, and Heeger (SSH). We have analyzed a variational solution with the displacement order parameter with as a variational parameter. It is shown within the weak-coupling limit that the soliton (creation) energy takes the minimum value with , where and are the dimerization energy gap and the Fermi velocity, respectively. These results agree quite well with numerical results by SSH for the discrete system. Furthermore, we show that the above is an exact solution of the self-consistent Bogoliubov-de Gennes equation.
- Received 14 August 1979
DOI:https://doi.org/10.1103/PhysRevB.21.2388
©1980 American Physical Society