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