Bound states of electrons with soliton-like excitations in thermal systems - adiabatic approximations

We study the bound states of electrons with solitonic excitations in one and two-dimensional atomic systems. We include Morse interactions between the atoms in a temperature range from low to physiological temperatures. The atoms are treated by classical Langevin equations. In a first approach, the places of compressions are visualized by drawing the overlap of the densities of the core electrons. Then we study the effect of nonlinear vibrations on the added, free electrons moving on the background of the atoms. We study the coupled classical and quantum-mechanical dynamics of the electrons on the lattice in tight-binding approximation (TBA). Further we consider the formation of solectrons, i. e., dynamic electron-soliton bound states in adiabatic approximations based on the energy spectrum and the canonical distribution

Controlling fast electron transfer at the nano-scale by solitonic excitations along crystallographic axes

We present computational evidence of the possibility of fast, supersonic or subsonic, nearly loss-free transport of electrons bound to lattice solitons along crystallographic axes in two-dimensional anharmonic crystal lattices

Nonlinear soliton-like excitations in two-dimensional lattices and charge transport

We study soliton-like excitations and their time and space evolution in several two-dimensional anharmonic lattices with Morse interactions: square lattices including ones with externally fixed square lattice frame (cuprate model), and triangular lattices. We analyze the dispersion equations and lump solutions of the Kadomtsev-Petviashvili equation. Adding electrons to the lattice we find solectron bound states and offer computational evidence of how electrons can be controlled and transported by such acoustic waves and how electron-surfing occurs at the nanoscale. We also offer computational evidence of the possibility of long lasting, fast lattice soliton and corresponding supersonic, almost loss-free transfer or transport of electrons bound to such lattice solitons along crystallographic axes

Soliton-like excitations and solectrons in two-dimensional nonlinear lattices

We discuss here the thermal excitation of soliton-like supersonic, intrinsic localized modes in two-dimensional monolayers of atoms imbedded into a heat bath. These excitations induce local electrical polarization fields at the nano-scale in the lattice which influence electron dynamics, thus leading to a new form of trapping. We study the soliton-mediated electron dynamics in such systems at moderately high temperatures and calculate the density of embedded electrons in a suitable adiabatic approximation. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011

Head-on and head-off collisions of discrete breathers in two-dimensional anharmonic crystal lattices

Collisions of discrete breathers (DB) moving toward each other along neighboring close packed atomic rows in a 2D crystal lattice are investigated by molecular dynamics computer simulations. It is shown that a DB can draw energy from the other and emerge from the collision with amplitude much greater than its initial amplitude

Thermodynamics of the rupture in a Morse lattice

The rupture of a Morse lattice is considered in the present paper. The critical rupture force Fcr is found to decrease with the number of particles N as Fcr ~ 1/$\sqrt{N}$. The partition function is obtained for two states of the lattice – with all equal bond lengths and one broken bond. In the first case an accurate expressions for thermodynamic parameters are obtained, and thermodynamic expressions are derived in the harmonic approximation in the latter case. The analytical predictions are confirmed by extensive MD simulations. Cis-trans isomerization is considered as an example. Volume fractions of trans- and cis-isomers versus number of monomer units N are found depending on the torsion stiffnesses