Density of neutral solitons in weakly disordered Peierls chains

Article

关键词: SCHRIEFFER-HEEGER MODEL;    QUANTUM-LATTICE MOTION;    CONJUGATED POLYMERS;    OPTICAL-ABSORPTION;    CONDUCTING POLYMERS;    TRANS-POLYACETYLENE;    CONTINUUM MODEL;    HUBBARD MODEL;    INSTABILITY;    SYSTEMS;   

DOI  :  10.1103/PhysRevB.57.2861

来源: SCIE

【 摘 要 】

We study the effects of weak off-diagonal disorder on Peierls systems with a doubly degenerate ground state. We show that for these systems disorder in the electron hopping amplitudes induces a finite density of solitons in the minimal-energy lattice configuration of a single chain. These disorder-induced dimerization kinks are neutral and have spin 1/2. Using a continuum model for the Peierls chain and treating the lattice classically, we analytically calculate the average free energy and density of kinks. We compare these results to numerical calculations for a discrete model and discuss the implications of the kinks for the optical and magnetic properties of the conjugated polymer trans-polyacetylene.

【 授权许可】

Free