Search results for "Particle in a one-dimensional lattice"
showing 5 items of 5 documents
An algorithm based in Ewald's method to calculate lattice sums in the framework of crystal field theory
1992
A simple procedure to help calculate the electrostatic potential at any point inside an ionic crystal is proposed and tested. The rationale for the mathematical algorithm to calculate lattice sums is based on Ewald's technique. The method is discussed with regard to the dimensions and shape of the crystal lattice. Electrostatic potential for NaCl and MgO type structures are obtained and compared with the values calculated by means of Ewald's method
On the lattice of J-subnormal subgroups
1992
Expansion of a quantum gas released from an optical lattice
2008
We analyze the interference pattern produced by ultracold atoms released from an optical lattice. Such interference patterns are commonly interpreted as the momentum distributions of the trapped quantum gas. We show that for finite time-of-flights the resulting density distribution can, however, be significantly altered, similar to a near-field diffraction regime in optics. We illustrate our findings with a simple model and realistic quantum Monte Carlo simulations for bosonic atoms, and compare the latter to experiments.
Generalised Kronig-Penney model for ultracold atomic quantum systems
2014
We study the properties of a quantum particle interacting with a one dimensional structure of equidistant scattering centres. We derive an analytical expression for the dispersion relation and for the Bloch functions in the presence of both even and odd scattering waves within the pseudopotential approximation. This generalises the well-known solid-state physics text-book result known as the Kronig-Penney model. Our generalised model can be used to describe systems such as degenerate Fermi gases interacting with ions or with another neutral atomic species confined in an optical lattice, thus enabling the investigation of polaron or Kondo physics within a simple formalism. We focus our atten…
Lattice quantum hadrodynamics
1992
Quantum corrections to the mean-field equation of state for nuclear matter are estimated in a lattice simulation of quantum hadrodynamics. In contrast with the standard coordinate-space methods used in lattice QCD, the calculations are carried out here in momentum space and on nonhypercubic (irregular) lattices. The quantum corrections to the known mean-field equation of state were found to be considerable.