We study the dynamics of bright solitons formed in a Bose-Einstein condensate with attractive atomic interactions perturbed by a weak bichromatic optical lattice potential. The lattice depth is a biperiodic function of time with a zero mean, which realizes a flashing ratchet for matter-wave solitons. We find that the average velocity of a soliton and the soliton current induced by the ratchet d...

We investigate laser-driven vibronic transitions of a single two-level atomic ion in harmonic and hard wall traps. In the Lamb-Dicke regime, for tuned or detuned lasers with respect to the internal frequency of the ion, and weak or strong laser intensities, the vibronic transitions occur at well isolated “Rabi Resonances”, where the detuning-adapted Rabi frequency coincides with the level spaci...

An investigation of the orientation and temperature dependence of domain wall properties in FePt is presented. The authors use a microscopic, atomic model for the magnetic interactions within an effective, classical spin Hamiltonian constructed on the basis of spin-density functional calculations. They find a significant dependence of the domain wall width as well as the domain wall energy on t...

We discuss the possibility of using pair-equations for the construction of the effective Hamiltonian H eff for valence electrons of an atom. The low-energy part of atomic spectrum is found by solving the eigenvalue problem for H eff. In this way it is possible to account efficiently for the valence-valence and core-valence correlations. We tested this method on a toy model of a four-electron at...

The magnetization dynamics of Co nanoislands on Cu(111) is studied on the atomic scale by means of the stochastic Landau-Lifshitz-Gilbert equation. The exchange and anisotropy constants of the spin Hamiltonian are computed from first principles. We focus on hysteresis loops and magnetic switching in dependence on temperature, island size, and strength of an external magnetic field. The magnetic...

The recoil of atoms in dense ensembles during light matter interactions is studied using quantized vibrational states for the atomic motion. resulting from forces due to near-field collective dipole and far-field laser decay are explored. contributions dependence on trap frequency different terms Hamiltonian Lindbladian studied. These calculations compared with previous results impulse model sl...

In a two-dimensional atomic Bose-Einstein condensate, we demonstrate Rashba spin-orbit coupling can always introduce dynamical instability into specific zero-quasimomentum states in all parameter regimes. During the evolution of states, such spin-orbit-coupling-induced fragment and lead to dynamically patterning process. The features formed patterns are identified from symmetries Bogoliubov-de ...

We present an accurate and efficient finite-difference formulation parallel implementation of Kohn-Sham Density (Operator) Functional Theory (DFT) for non periodic systems embedded in a bulk environment. Specifically, employing non-local pseudopotentials, local reformulation electrostatics, truncation the spatial Hamiltonian, Linear Scaling Spectral Quadrature method to solve pointwise electron...