Related papers: Many-body effects in the mesoscopic x-ray edge pro…
The many-body theory of photoemission in solids is reviewed with emphasis on methods based on response theory. The classification of diagrams into loss and no-loss diagrams is discussed and related to Keldysh path-ordering book-keeping.…
The x-ray absorption near edge structure (XANES), developed in these last 40 years using synchrotron radiation, is a unique tool probing electronic correlations in complex systems via quantum many body final state effects. Multi electron…
The effects of point defects on the loss of either energies of ballistic electron beams or incident photons are studied by using a many-body theory in a multi-quantum-well system. This includes the defect-induced vertex correction to a bare…
Some recent results concerning nonlinear optics in semiconductor microcavities are reviewed from the point of view of the many-body physics of an interacting photon gas. Analogies with systems of cold atoms at thermal equilibrium are drawn,…
The many-body mobility edge (MBME) in energy, which separates thermal states from many-body localization (MBL) states, is a critical yet controversial concept in MBL physics. Here we examine the quasiperiodic $t_1-t_2$ model that features a…
We present a new theoretical approach to describe X-Ray absorption and Magnetic Circular Dichroism spectra in the presence of e-e correlation. Our approach provides an unified picture to include correlations in both charged and neutral…
Many-body localization for a system of bosons trapped in a one dimensional lattice is discussed. Two models that may be realized for cold atoms in optical lattices are considered. The model with a random on-site potential is compared with…
Many body effects on spin dynamics in semiconductors have attracted a lot of attentions in recent years. In this paper, we show why and how the many body effects have to be considered by a simple Bloch sphere geometry approach. The micro…
We study many-body localization in a one dimensional optical lattice filled with bosons. The interaction between bosons is assumed to be random, which can be realized for atoms close to a microchip exposed to a spatially fluctuating…
As disorder strength increases in quantum many-body systems a new phase of matter, the so-called anybody localization, emerges across the whole spectrum. This transition is energy dependent, a phenomenon known as mobility edge, such that…
A description of a large system of particles is often sought in a derivation from the detailed behaviour of just a few of the particles. The present thesis deals with the connection between such microscopic features and the nature of a…
Intersubband polaritons are light-matter excitations originating from the strong coupling between an intersubband quantum well electronic transition and a microcavity photon mode. In this paper we study how the Coulomb electron-electron…
Transient X-ray absorption techniques can measure ultrafast dynamics of the elemental edges in a material or multiple layer junction, giving them immense potential for deconvoluting concurrent processes. However, the interpretation of the…
We find that, in the mesoscopic regime, modification of the material's surface can induce an extensive change of the material's magnetic moment. In other words, perturbation of order $N^2$ atoms on the surface of a 3-dimensional solid can…
Angular resolved photoelectron spectra of metal clusters have been experimentally measured for the first time only recently. These measurements have been performed systematically for sodium clusters in a broad range of cluster sizes. This…
While highly successful, density functional theory is known to have limitations owing to its neglect of many-body electron-electron interactions. This neglect leads to errors in the single-particle energies, leading to underestimated band…
We have studied the Stark effect in the soft x-ray region for various small molecules by calculating the field-dependent x-ray absorption spectra. This effect is explained in terms of the response of molecular orbitals (core and valence),…
The existence of many-body mobility edges in closed quantum systems has been the focus of intense debate after the emergence of the description of the many-body localization phenomenon. Here we propose that this issue can be settled in…
In this work the influence of many-electron effects on the shape of characteristic X-ray emission bands of the simple metals Mg and Al are examined by means of ab initio calculations and semi-empirical models. These approaches are also used…
Ab initio calculations have been carried out to study the magnetic dipole and electric quadrupole hyperfine structure constants of $^{205}$Pb$^+$. Many-body effects have been considered to all orders using the relativistic coupled-cluster…