Open Quantum systems
Jérémie Leonard (IPCMS) and Shannon Whitlock (ISIS)
Introduction to the formalism for the description of a quantum system interacting with a
thermal bath: concepts of density matrix, populations, coherences, damping, dephasing,
Master Equation. Model of the bath of harmonic oscillators. Perturbation theory and
application to the light–matter interaction. (i) linear response and correlation functions:
UV–Vis spectroscopy. (ii) non linear response: non linear spectroscopy as a tool for the
investigation of ultrafast processes. Coherent versus incoherent dynamics. Introduction
to the corresponding experimental approaches (femtosecond spectroscopy). Illustration
with dilute systems in condensed phase, and molecular systems in particular.
Objectives: understanding and using the general tools and concepts for the
description of a quantum system interacting with its environment, which are
relevant for quantum sciences and technologies in general. Application of these
concepts to the investigation of light–matter interaction, with a focus on dilute
systems in condensed phase (in particular molecules). Learning about the
principals and implementation of ultrafast spectroscopy for the investigation of
ultrafast photoinduced processes in such open systems.