"Theoretical second-order nonlinear optical spectroscopy: towards the design of new materials"

Eleonora Luppi, Associate Professor, Laboratoire de Chimie Théorique, Sorbonne Université, Paris, France

March 12th (Monday), 10:00am
Engineering Science Building (ESB), Rm 1001

Nonlinear optics is an important and exciting field of fundamental and applied research, with applications in many different disciplines such as physics, chemistry, material science and biology. In recent years, nonlinear optical phenomena started to be also widely used in technological applications for optoelectronics and photovoltaics. This coincided with an important experimental and theoretical search for new materials with an efficient and exploitable nonlinear optical response. In this seminar I will present the theoretical formalism in Time-Dependent Density-Functional Theory (TDDFT) I developed in order to calculate the nonlinear optical spectroscopy: second-harmonic generation. I will show the different level of approximation of the many-electrons interactions (local fields and excitons) that this formalism can describe which are fundamental in the interpretation of the experiments. The impact of the theory will then be analyzed on different classes of materials: Si strained, Si/Ge heterostructures and Si surfaces.

About Eleonora Luppi:

Photo of Eleonora Luppi Since 2012, Dr. Eleonora Luppi is associate professor at the Sorbonne University Paris, France. She got her PhD in 2006 with Prof. Ossicini working on ab-initio studies of Si nanocrystal. From 2006 to 2010 she was postdoctoral researcher with Dr. Valerie Veniard at Laboratoire des Solides Irradiés Ecole Polytechnique, France working on nonlinear optics in solids and from 2010 to 2012 she was postdoctoral researcher in Prof. Martin Head-Gordon’s group at University of California Berkeley, Department of Chemistry, Berkeley, USA working on nonlinear optics in molecular systems. The main research interests of Dr. Luppi concern the theoretical development of ab-initio approaches for the calculation of linear and nonlinear optical properties of atoms, molecules and solids. These theoretical developments have been implemented in numerical codes. She is the coordinator of the software project 2light for the calculation of second- and third-order nonlinear optical properties of solids in TDDFT and of light code for the description of the electrons dynamics of atoms and molecules under laser excitations using time-dependent wavefunction methods.

Hosted by: Professor John Bowers, Dr. Paolo Pintus