Category Archives: many body perturbation theory

Exciton-phonon coupling tutorial

A new tutorial on exciton-phonon coupling in Yambo is available. In this tutorial we will show how to generate exciton-phonon matrix elements and calculate phonon-assisted absorption and emission. In the last part of the tutorial the exciton-phonon matrix elements will be used to calculate exciton life-time. The tutorial is based on a preliminary version of… Read More

Luminescence in hexagonal boron nitride single layer: exciton-phonon coupling and the role of substrate

In this new work we study luminescence in monolayer hexagonal boron nitride (m-hBN) using a new ab-initio approach that takes into account the effects of atomic vibrations on the luminescence spectra. We construct the dynamical exciton-phonon self-energy, then use it to perturbatively correct the optical response functions and test this approach on bulk hBN as… Read More

Yambo school 2020: new video lectures and tutorials are online

The “Computational School on Electronic Excitations in Novel Materials Using the Yambo Code” school at the ICTP has just ended. In this school we presented an introduction to many-body theory, a new version of the code that include all the non-linear response part. The new tutorials that are available in the wiki webpage. Moreover all… Read More

Computational School on Electronic Excitations in Novel Materials Using the Yambo Code

The Computational School on Electronic Excitations in Novel Materials Using the Yambo Code, introduces participants to post-DFT simulations, in particular many-body perturbation theory (MBPT) approaches and provide training in the calculation of electronic and optical properties of materials. The program will offer theoretical and technical lectures, as well as dedicated hands-on sessions where the students… Read More

Theory of phonon-assisted luminescence

In this presentation I present the theory of phonon-assisted luminescence, in terms of non-equilibrium  Green’s functions and time-dependent perturbation theory. We derived a simple formule for light emission in the limit of low excited carriers including excitonic effects and then included coupling with phonons by time-dependent perturbation theory. This approach is then applied to the… Read More