DFT and TDDFT Calculations of Ground and Excited States of Photoelectron Emission

Abstract

The Density-Functional Theory (DFT) is a reformulation of the quantum study of a correlated N-body system into a simpler system with independent equations being solved iteratively. The DFT considers only ground states of the systems. The extension to the time-dependent case of this theory is the Time-Dependent Density-Functional Theory (TDDFT) that also takes into account the excited states of the system. These calculations are very interesting in photonics areas. In fact, the interaction between electrons and light in the vicinity of solid surfaces and nanostructures is important as pathway to integrate photonics and electronics. The capability to couple light and electrons in purposefully designed device depends on the capability of creating such devices and the understanding of the underlying science.