Accession Number : ADA316999

Title :   Monte Carlo Studies of Continuous Hamiltonian Systems Coupled to Dissipative Mechanisms.

Descriptive Note : Final rept. 1 Apr 93-31 Aug 96,

Corporate Author : DUKE UNIV DURHAM NC

Personal Author(s) : Ciftan, Mikael

PDF Url : ADA316999

Report Date : OCT 1996

Pagination or Media Count : 7

Abstract : My staff research on dissipative Hamiltonian systems has evolved from Quantum Optics into three areas over the past three years, exemplifying the type coherent and incoherent processes which when merged lead to dissipative relaxation: (1) High precision scaling and critical exponent relations were derived for the Heisenberg Ferromagnet which show new details that challenge existing theories; (2) Super-enhanced Backscattering of radiation was observed and explained as due to Fabry-Perot type multi-pass multiple scattering from rough thin films where coherency is broken by the spatial stochasticity of the medium leading to photon localization and the ensuing enhancement. Next we need to take higher order correlations into account to include memory effects akin to hysteresis that we studied in Quantum Optics; (3) Showed the necessity of taking the full potential (as opposed to muffin-tin potentials which are partials of the full potential) in the Wigner-Seitz cells of crystalline solids for the calculation of electronic energy levels, including the role of impurities such as sulfur and boron, and therefrom deriving microscopic stress-strain tonsorial relations to study crack propagation-embrittlement problems at the level of details of bonding orbitals. Next Molecular Dynamics will be performed to show effects of temperature on this micromechanical dynamics.

Descriptors :   *QUANTUM THEORY, *CRACK PROPAGATION, *HAMILTONIAN FUNCTIONS, STRESS STRAIN RELATIONS, STOCHASTIC PROCESSES, THIN FILMS, SURFACE ROUGHNESS, EMBRITTLEMENT, BACKSCATTERING, MONTE CARLO METHOD, ELECTRON ENERGY, OPTICAL ANALYSIS, ELECTRONIC STATES, SYSTEMS ANALYSIS, MICROMECHANICS, FERROMAGNETISM, MOLECULAR ENERGY LEVELS.

Subject Categories : Quantum Theory and Relativity
      Mechanics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE