Numerical evidence of electron-soliton dynamics in Fermi-Pasta-Ulam disordered chains

作者：de Moura F A B F^*

来源：Physica D: Nonlinear Phenomena , 2013, 253: 66-72.

DOI：10.1016/j.physd.2013.02.013

• Wavepacket dynamics
• Soliton
• Electron-phonon interaction

In this paper, we study numerically the one-electron dynamics in a Fermi-Pasta-Ulam disordered chain. In our model the atoms are coupled by a random harmonic force and a nonlinear cubic potential. The electron lattice interaction was considered such that the kinetic energy of the electrons depends on the effective distance between neighboring atoms. Basically, the hopping term will increase exponentially when the distance between neighboring atoms decreases. By solving numerically the equations describing the dynamics for the electron and lattice, we can compute the spreading of an initially localized electronic wavepacket. Our results suggest that the soliton excitation induced by the nonlinear cubic interaction present in the Hamiltonian can control the electron dynamics across the entire lattice. We report numerical evidence of the existence of a soliton-electron pair in Fermi-Pasta-Ulam disordered chains. We discuss in detail the conditions necessary for promoting the electron transport mediated by solitons in this model.

• 出版日期2013-6-15