@article{322, keywords = {ab-initio, excited states, paper}, author = {Maurizia Palummo and M. Bruno and Olivia Pulci and E Luppi and Elena Degoli and Stefano Ossicini and Rodolfo Del Sole}, title = {Ab-initio electronic and optical properties of low dimensional systems: From single particle to many-body approaches}, abstract = {Low dimensional systems, such as nanodots, nanotubes, nanowires, have attracted great interest in the last years, due to their possible application in nanodevices. It is hence very important to describe accurately their electronic and optical properties within highly reliable and efficient ab-initio approaches. Density functional theory (DFT) has become in the last 20 years the standard technique for studying the ground-state properties, but this method often shows significant deviations from the experiment when electronic excited states are involved. The use of many-body Green\textquoterights functions theory, with DFT calculations taken as the zero order approximation, is today the state-of-the-art technique for obtaining quasi-particle excitation energies and optical spectra. In this paper we will present the current status of this theoretical and computational approach, showing results for different kinds of low dimensional systems. (C) 2007 Elsevier B.V. All rights reserved.}, year = {2007}, journal = {SURFACE SCIENCE}, volume = {601}, number = {13}, pages = {2696-2701}, month = {JUL 1}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, url = {http://dx.doi.org/10.1016/j.susc.2006.12.019}, doi = {10.1016/j.susc.2006.12.019}, note = {International Conference on NANO-Structures Self Assembling, Aix en Provence, FRANCE, JUL 02-06, 2006}, }