Excitonic and solitonic states in one‐dimensional exciton–phonon systems

A one‐dimensional model for Frenkel excitons interacting with acoustical phonons via a linear diagonal coupling is studied using two distinct variational trial functions which lead to delocalized (excitonic) and localized (solitonic) states. Above a certain exciton–phonon coupling strength, which depends on the exciton band width and the Debye frequency of the phonons, the soliton ground state energy lies below the continuum of dressed excitons. For exciton bandwidths not much larger than the Debye frequency this occurs in a regime where the continuum approximation for the soliton is invalid.

[1]  E. Knapp,et al.  Exciton-phonon self-trapping: A continuous transition , 1984 .

[2]  M. A. Collins,et al.  A model of localization, soliton propagation, and self-trapping in an electronically excited atomic lattice , 1983 .

[3]  Alwyn C. Scott,et al.  Dynamics of Davydov solitons , 1982 .

[4]  A. Davydov,et al.  The role of solitons in the energy and electron transfer in one-dimensional molecular systems , 1981 .

[5]  J. Hyman,et al.  On Davydov's alpha-helix solitons , 1981 .

[6]  A. Heeger,et al.  Soliton excitations in polyacetylene , 1980 .

[7]  D. Yarkony,et al.  Comments on exciton phonon coupling: Temperature dependence , 1976 .

[8]  A. Davydov,et al.  Solitons in One-Dimensional Molecular Chains , 1976 .

[9]  R. Knox,et al.  Theory of Molecular Excitons , 1964 .

[10]  R. Merrifield.  Theory of the Vibrational Structure of Molecular Exciton States , 1964 .

[11]  Y. Toyozawa.  Self-Trapping of an Electron by the Acoustical Mode of Lattice Vibration. I , 1961 .

[12]  T. Holstein,et al.  Studies of polaron motion: Part II. The “small” polaron , 1959 .

[13]  R. Peierls,et al.  Quantum theory of solids , 1956 .

[14]  F. Low,et al.  The Motion of Slow Electrons in a Polar Crystal , 1952 .

[15]  P. Scherer,et al.  On the theory of vibronic structure of linear aggregates. Application to pseudoisocyanin (PIC) , 1984 .

[16]  H. Haken,et al.  Organic Molecular Aggregates , 1983 .

[17]  D. Emin.  On the existence of free and self-trapped carriers in insulators: an abrupt temperature-dependent conductivity transition , 1973 .