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State Physics (state + physics)

Distribution by Scientific Domains
Physics and Astronomy60%

Kinds of State Physics

  • solid state physics
    		•

    Selected Abstracts

    Conserving Galerkin weak formulations for computational fracture mechanics

    INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 12 2002
    Shaofan Li
    Abstract In this paper, a notion of invariant Galerkin-variational weak forms is proposed. Two specific invariant variational weak forms, the J-invariant and the L-invariant, are constructed based on the corresponding conservation laws in elasticity, one of which is the conservation of Eshelby's energy-momentum (Eshelby. Philos. Trans. Roy. Soc. 1951; 87: 12; In Solid State Physics, Setitz F, Turnbull D (eds). Academic Press: New York, 1956; 331; Rice, J. Appl. Mech. 1968; 35: 379). It is shown that the finite element solution obtained from the invariant Galerkin weak formulations proposed here can conserve the value of J-integral, or L-integral exactly. In other words, the J and L integrals of the Galerkin finite element solutions are path independent in the discrete sense. It is argued that by using the J-invariant Galerkin weak form to compute near crack-tip field in an elastic solid, one may accurately calculate the crack extension energy release rate and subsequently the stress intensity factors in numerical computations, because the flux of the energy-momentum is conserved in discrete computations. This may provide an alternative means to accurately simulate crack growth and propagation. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    Optical, electrical and structural characterization of CuInSe2 thin films

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 9 2005
    C. Calderón
    The present issue of physica status solidi (b) comprises papers presented at the XVII Latin American Symposium on Solid State Physics (SLAFES 2004) in Havana, Cuba, 6,9 December 2004. Further papers from this conference are published in phys. stat. sol. (c) 2, No. 10 (2005). The cover picture refers to the article [1] on polycrystalline CuInSe2 films by Clara Calderón et al. and shows the crystal structure of CuInSe2 (right) and that of the In-rich phase CuIn3Se5 (left) which were used for the simulation and analysis of the X-ray diffraction spectra. Clara Lilia Calderón Triana is teacher at the Solar Cells Laboratory of Universidad Nacional de Colombia in Bogotá where she has been working on solar cells and semiconductor materials since 1995. In particular, she is fabricating thin film solar cells based on CuInSe2 and Cu(In,Ga)Se2. At SLAFES 2004, Clara Calderón received the physica status solidi Young Researcher Award for her second presentation entitled "Study of electrical transport properties of ZnO thin films used as front contact of solar cells" [2] which is published as Editor's Choice of this issue. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Preface: phys. stat. sol. (c) 1/9

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2004
    Andrew Leitch
    The Conference on Photo-responsive Materials took place at the Kariega Game Reserve in the Eastern Cape, South Africa from 25,29 February 2004. More than 60 delegates from 12 different countries participated in the four-day event. The purpose of the conference was to bring together scientists working on various aspects of photo-responsive materials, so as to stimulate this important field of solid state physics in Southern Africa. As may be seen from the list of papers appearing in these proceedings, there was much interest in copper indium diselenide as a thin film material for photovoltaic applications. Also worth mentioning were the valuable contributions on ZnO, GaN and other materials that are currently attracting attention worldwide. The conference program allowed sufficient time for interaction and exchanging of views. Being in a game reserve in the heart of the beautiful Eastern Cape, delegates were also taken on game drives and had the opportunity of taking a river cruise up the Kariega River to view the majestic fish eagle. The members of the academic program committee were: Vivian Alberts (Rand Afrikaans University), Danie Auret (University of Pretoria), Darrell Comins (University of the Witwatersrand), and Reinhardt Botha and Andrew Leitch (University of Port Elizabeth). All papers appearing in these proceedings underwent a strict reviewing process separate from the conference. We express our appreciation to the referees for their diligence in this important task. The conference was organized by the Department of Physics at the University of Port Elizabeth, under the auspices of the Condensed Matter Physics and Materials Science (CMPMS) subgroup of the South African Institute of Physics. It was sponsored by EMF Limited (UK), Sensors Unlimited Inc. (USA), and Carl Zeiss (Pty) Ltd. Special thanks must go to Dr Eunete van Wyk for her professional assistance in the preparation of these proceedings. [source]

    The posthumous impact of Paul Drude,

    ANNALEN DER PHYSIK, Issue 7-8 2006
    M. Cardona
    Abstract In this study the long-term impact of the works of Paul Drude has been analyzed by bibliometric methods. His overall citation impact and rank within the pre-1910 authors in chemistry and physics has been determined. The time-dependent number of mentions of his name, the overall citation impact and the citation numbers of single articles and books have been investigated. The impact time curves of his most frequently cited articles and books are presented and discussed. The scientific contributions of the most influential Drude works for solid state physics are analyzed, in particular their impact on recent research. [source]

    Semiclassical limit for the Schrödinger-Poisson equation in a crystal

    COMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 7 2001
    Philippe Bechouche
    We give a mathematically rigorous theory for the limit from a weakly nonlinear Schrödinger equation with both periodic and nonperiodic potential to the semiclassical version of the Vlasov equation. To this end we perform simultaneously a classical limit (vanishing Planck constant) and a homogenization limit of the periodic structure (vanishing lattice length taken proportional to the Planck constant). We introduce a new variant of Wigner transforms, namely the "Wigner Bloch series" as an adaption of the Wigner series for density matrices related to two different "energy bands." Another essential tool are estimates on the commutators of the projectors into the Floquet subspaces ("band subspaces") and the multiplicative potential operator that destroy the invariance of these band subspaces under the periodic Hamiltonian. We assume the initial data to be concentrated in isolated bands but allow for band crossing of the other bands which is the generic situation in more than one space dimension. The nonperiodic potential is obtained from a coupling to the Poisson equation, i.e., we take into account the self-consistent Coulomb interaction. Our results hold also for the easier linear case where this potential is given. We hence give the first rigorous derivation of the (nonlinear) "semiclassical equations" of solid state physics widely used to describe the dynamics of electrons in semiconductors. © 2001 John Wiley & Sons, Inc. [source]