Stochastic Galerkin Methods for the Boltzmann-Poisson system

Jose Morales Escalante (UT San Antonio)

Jun 14. 2022, 16:00 — 16:45

We study uncertainty quantification for a Boltzmann-Poisson system
that models electron transport in semiconductors and the physical collision mechanisms over the charges, using the stochastic Galerkin method in order to handle the randomness associated with the problem. In this study
we choose first as a source of uncertainty the phonon energy, taking it as
a random variable, as its value influences the energy jump appearing in
the collision integral for electron-phonon scattering. Then we choose the
lattice temperature as a random variable since it defines the value of the
collision operator terms in the case of electron-phonon scattering by being
a parameter of the phonon distribution. Finally, we present our numerical simulations for the latter case. We calculate then with our stochastic Discontinuous Galerkin methods the uncertainty in kinetic moments such
as density, mean energy, current, etc. associated with a possible physical
temperature variation (assumed to follow a uniform distribution) in the
lattice environment, as this uncertainty in the temperature is propagated into the electron PDF. Our mathematical and computational results let us predict then in a real-world problem setting the impact that possible variations in the lab conditions (such as temperature) or limitations in the mathematical model (such as the assumption of constant phonon energy) will have over the uncertainty in the behavior of electronic devices. This work is done in collaboration with Prof. Clemens Heitzinger from TU Wien IASC.

Further Information
ESI Boltzmann Lecture Hall
Associated Event:
Computational Uncertainty Quantification: Mathematical Foundations, Methodology & Data (Thematic Programme)
Clemens Heitzinger (TU Vienna)
Fabio Nobile (EPFL, Lausanne)
Robert Scheichl (U Heidelberg)
Christoph Schwab (ETH Zürich)
Sara van de Geer (ETH Zürich)
Karen Willcox (U of Texas, Austin)