Dynamics of interacting electrons under effect of a Morse potential.

We consider interacting electrons moving in a nonlinear Morse lattice. We set the initial conditions as follows: electrons were initially localized at the center of the chain and a solitonic deformation was produced by an impulse excitation on the center of the chain. By solving quantum and classical equations for this system numerically, we found that a fraction of electronic wave function was trapped by the solitonic excitation, and trapping specificities depend on the degree of interaction among electrons. Also, there is evidence that the effective electron velocity depends on Coulomb interaction and electron-phonon coupling in a nontrivial way. This association is explained in detail along this work. In addition, we briefly discuss the dependence of our results with the type of initial condition we choose for the electrons and lattice.

Sub-diffusive electronic transport in a DNA single-strand chain with electron-phonon coupling.

We investigate the electronic wavepacket dynamics in a finite segment of a DNA single-strand chain considering the electron-phonon coupling. Our theoretical approach makes use of an effective tight-binding Hamiltonian to describe the electron dynamics, together with a classical harmonic Hamiltonian to treat the intrinsic DNA vibrations. An effective time-dependent Schrödinger equation is then settled up and solved numerically for an initially localized wave-packet using the standard Dormand-Prince eighth-order Runge-Kutta method. Our numerical results indicate the presence of a sub-diffusive electronic wavepacket spread mediated by the electron-phonon interaction.

Electron-soliton dynamics in chains with cubic nonlinearity.

In our work, we consider the problem of electronic transport mediated by coupling with solitonic elastic waves. We study the electronic transport in a 1D unharmonic lattice with a cubic interaction between nearest neighboring sites. The electron-lattice interaction was considered as a linear function of the distance between neighboring atoms in our study. We numerically solve the dynamics equations for the electron and lattice and compute the dynamics of an initially localized electronic wave-packet. Our results suggest that the solitonic waves that exist within this nonlinear lattice can control the electron dynamics along the chain. Moreover, we demonstrate that the existence of a mobile electron-soliton pair exhibits a counter-intuitive dependence with the value of the electron-lattice coupling.

Energy transport in a one-dimensional harmonic ternary chain with Ornstein-Uhlenbeck disorder.

In this paper we study a one-dimensional ternary harmonic chain with the mass distribution constructed from an Ornstein-Uhlenbeck process. We generate a ternary mass disordered distribution by generating the correlated Ornstein-Uhlenbeck process and mapping it into a sequence of three different values. The probability of each value is controlled by a fixed parameter b. We analyze the localization aspect of the above model by numerical solution of the Hamilton equations and by the transfer matrix formalism. Our results indicate that the correlated ternary mass distribution does not promote the appearance of new extended modes. In good agreement with previous work, we obtain extended modes for b â†’ ∞; however, we explain in detail the main issue behind this apparent localization- delocalization transition. In addition, we obtain the energy dynamics for this classical chain.