Search results for "Surface Science"

Preface

2012

Bill2d — A software package for classical two-dimensional Hamiltonian systems

2019

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract We present Bill2d, a modern and efficient C++ package for classical simulations of two-dimensional Hamiltonian systems. Bill2d can be used for various billiard and diffusion problems with one or more charged particles with interactions, different external potentials, an external magnetic field, periodic and open boundaries, etc. The software package can also calculate many key quantities in complex systems such as Poincaré sections, survival probabilities, and diffusion coefficients. While ai... Title of program: Bill2d Catalogue Id: AEYL_v1_0 Nature of problem Numerical propa…

Imaginary time propagation code for large-scale two-dimensional eigenvalue problems in magnetic fields

2019

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract We present a code for solving the single-particle, time-independent Schrödinger equation in two dimensions. Our program utilizes the imaginary time propagation (ITP) algorithm, and it includes the most recent developments in the ITP method: the arbitrary order operator factorization and the exact inclusion of a (possibly very strong) magnetic field. Our program is able to solve thousands of eigenstates of a two-dimensional quantum system in reasonable time with commonly available hardware. Th... Title of program: itp2d Catalogue Id: AENR_v1_0 Nature of problem Numerical calcul…

Focus on the Essential: Extracting the Decisive Energy Barrier of a Complex Process

2019

Molecular processes at surfaces can be composed of a rather complex sequence of steps. The kinetics of even seemingly simple steps are demonstrated to depend on a multitude of factors, which prohibits applying a simple Arrhenius law. This complexity can make it challenging to experimentally determine the kinetic parameters of a single step. However, a molecular-level understanding of molecular processes such as structural transitions requires elucidating the atomistic details of the individual steps. Here, a strategy is presented to extract the energy barrier of a decisive step in a very complex structural transition by systematically addressing all factors that impact the transition kineti…

Surface Physics With Slow Positrons

1983

Recent progress in slow beam studies of positron-surface interactions is reviewed. The key physical phenomena are introduced, and the present knowledge of the parameters involved is reviewed. The potential of the slow positron technique for surface science is discussed.

Near-field optics theories

1996

The development of near-field optics theory is reviewed. We first recall that near-field optics is not limited to near-field microscopy. Broadly speaking, it concerns phenomena involving evanescent electromagnetic waves. The importance of such waves was ignored for a long time in optical and surface physics until the emergence of scanning near-field optical microscopes. Taking evanescent waves into account prevents the use of any simple approximation in the set of Maxwell's equations. The various theoretical approaches of near-field optics are discussed from the point of view of their ability to assess evanescent electromagnetic waves. We discuss the main results of the application of the v…

Surface Studies with Slow Positron Beaks

1984

Slow-positron physics is an exciting and rapidly advancing field. The continuing progress in the development of intense monochromatic beams of low-energy positrons has made it possible to perform a number of landmark experiments, where the interaction of the positron with solid surfaces plays a central role. These experiments either deal with fundamental atomic physics (positronium spectroscopy) or focus on the electronic and atomic properties of the surface region, using positrons as a probe. In the former category, the surface is involved just as an efficient source of positronium-like atoms. On the other hand, in the second category of experiments the surface i s the main object of study…