
Do you still buy scientific books? DOWNLOAD THEM!!!!!!
FreeScience.info provides more than 2000 free scientific books. 
Search for a Book





What's (the) Matter?, A Show on Elementary Particle Physics. 
Posted on 20161017
(Send to a Friend )


We present the screenplay of a physics show on particle physics, by the Physikshow of Bonn University. The show is addressed at nonphysicists aged 14 and communicates basic concepts of elementary particle physics including the discovery of the Higgs boson in an entertaining fashion. It is also demonstrates a successful outreach activity heavily relying on the university physics students. This paper is addressed at anybody interested in particle physics and/or show physics. This paper is also addressed at fellow physicists working in outre . . . . 






The historical development of Xray Absorption Fine Spectroscopy and of its applications to Materials Science 
Posted on 20161012
(Send to a Friend )


This essay sketches the development of Xray Absorption Fine Spectroscopy (XAFS) ever since the second half of 20th century. At that time, synchrotrons started competing with Xray discharge tubes as the sources of the excitation able to show the pre and nearedge structures (XANES) and extended oscillations (EXAFS) that characterize the Xray absorption edge of solid matter. Actually, modern XAFS began after 1975, when the hardXray synchrotron radiation derived from storage rings took over. Ever since, XAFS greatly contributed to both techn . . . . 






Dynamical Screening Effects in Correlated Electron Materials  A Progress Report on Combined ManyBody Perturbation and DMFT 
Posted on 20161012
(Send to a Friend )


We give a summary of recent progress in the field of electronic structure calculations for materials with strong electronic Coulomb correlations. The discussion focuses on developments beyond the by now well established combination of density functional and dynamical mean field theory dubbed "LDA DMFT". It is organized around the description of dynamical screening effects in the solid. Indeed, screening in the solid gives rise to dynamical local Coulomb interactions U(w) (Aryasetiawan et al 2004 Phys. Rev. B 70 195104), and this frequ . . . . 






Nonlinear response in extended systems: a realtime approach 
Posted on 20161012
(Send to a Friend )


In this thesis we present a new formalism to study linear and nonlinear response in extended systems. Our approach is based on realtime solution of an effective Schr\"odinger equation. The coupling between electrons and external field is described by means of Modern Theory of Polarization. Correlation effects are derived from Green's function theory. We show that the inclusion of localfield effects and electronhole interaction is crucial to predict and reproduce second and third harmonic generation in low dimensional structures, where . . . . 






Quantum theory of spontaneous emission and coherent effects in semiconductor microstructures 
Posted on 20161012
(Send to a Friend )


A fully quantummechanical theory for the interaction of light and electron
}
hole excitations
in semiconductor quantumwell systems is developed. The resulting manybody hierarchy for
the correlation functions is truncated using a dynamical decoupling scheme leading to coupled
semiconductor luminescence and Bloch equations. For incoherent excitation conditions, the
theory is used to describe nonlinear excitonic emission properties of singlequantum wells,
optically coupled multiple quantumwell systems, and quantum wells in a microcavit . . . . 






Quasiparticle SelfConsistent GW Method for the Spectral Properties of Complex Materials 
Posted on 20161011
(Send to a Friend )


The GWapproximation to the formally exact manybody perturbation
theory has been applied successfully to materials for several decades. Since the
practical calculations are extremely cumbersome, the GW selfenergy is most
commonly evaluated using a firstorder perturbative approach: This is the
socalled G0W0 scheme. However, the
G0W0 approximation depends heavily on
the meanfield theory that is employed as a basis for the perturbation theory.
Recently, a procedure to reach a kind of selfconsistency within the
GW framework has been pr . . . . 






