Theoretical x-ray spectroscopy *

When:
07/07/2016 @ 2:00 PM – 3:00 PM
2016-07-07T14:00:00+08:00
2016-07-07T15:00:00+08:00

Speaker: 

Claudia Draxl (Humboldt University of Berlin, Germany)

Date: 

Thu, 07/07/2016 – 2:00pm to 3:00pm

Location: 

CA2DM Theory Common (S16-06)

Event Type: 

Seminars

* a joint CA2DM/NUSNNI/SSLS seminar

Abstract

Ab initio spectroscopy is a powerful combination of quantum-based theories and computer simulations. It covers a wide range of theoretical and computational methods, which go beyond density-functional theory by incorporating many-body effects and interactions that show up in the excited state. This methodology not only allows for analyzing data obtained by experimental probes like photoemission, optical absorption, Raman, infrared, x-ray, and electron-loss spectroscopy, but also for shining light onto the underlying processes. These may be distinctively different depending on the nature and dimensionality of the material.

In this talk, I will focus on core excitations, discussing different absorption edges in a variety of systems. These will cover carbon-based materials, ranging from graphene to self-assembled monolayers of molecular switches and inorganic semiconductors, ranging from nitrides to wide-gap oxides. Discuss their exciton binding strength and character, I will show how theory can get insight into the exciting phenomena behind the spectral features.

About the speaker

Prof. Claudia Draxl is Professor at the Humboldt-Universität zu Berlin and Felllow of the Max Planck Society. Her research is dedicated to condensed-matter theory and computational materials science, spanning theorectical concepts, development of computer codes, as well their application to a variety of materials. Her team is developing exciting – an all-electron full-potential computer package implementing DFT, TDDFT, and many-body perturbation theory. A particular focus is theoretical spectroscopy – the quantum-based description of radiation-matter interaction. Actual research projects concern organic/inorganic hybrid structures, molecular switches on surfaces, thermoelectricity, semiconductor nanostructures, solar-cell materials, organic film-growth, and more.