Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing
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Antoine Aerts

Background

  • BA in chemistry, ULB (2012-2015)
  • MA in chemistry, ULB, research focus program (2015-2017)
  • Internship: Nuclear Quadrupole Coupling Constants of Aluminum Compounds : A Computational Study, University of Alberta (2016)
  • Master thesis: Contrôle laser d’un système Markovien, ULB (2017)
  • Prix Ilya Prigogine (2017)
  • Prix Solvay (2017)
  • PhD in chemistry, ULB, (2017-present)
  • Teaching assistant ,ULB, CHIM-F101 : chimie générale, (2017-present)

PhD project

Towards the laser control of open quantum systems.
Controlling reactivity through molecular motion at the quantum level is a most challenging and long-standing goal in chemistry. In this respect, lasers are essential tools to manipulate the population of molecular states and therefore favor the outcome of chemical reactions. In the beginning of the 90’s, Rabitz and coauthors theoretically proposed an exciting new way, based on the design of a single laser pulse to control molecular motion. It gave birth to the so-called “optimal control theory”.
Experimentally, control strategies based on the use of theoretical laser pulses constructed on the Rabitz’ scheme faced major issues mainly because (1) the theoretical Hamiltonians used to describe the molecular systems and intramolecular vibrational redistribution (IVR) [4] were not realistic enough; (2) the system-environment interaction is critical and was so far rarely theoretically considered; (3) the theoretically predicted shape of the pulses was generally unrealistic given instrumental limitations.
The goal of the present project is to overcome some of the limitations just mentioned. We want to develop sophisticated theoretical algorithms to design optimal pulses coping with experimental constraints. The use of global effective Hamiltonian to describe the molecular system will also ensure that the structural set of parameters necessary to design the pulse will be as close to the experimental observations as possible.
A major problem encountered experimentally in controlling quantum systems is the dissipation due to interactions with the environment. Theoretically, the effects of the environment can be included in the Markov approximation through, for example, the Lindblad equations, leading to more robust control schemes. In the frame of the present project, we will try to extract these parameters from experimentally measured line broadening coefficients. In particular, studies of pressure effects on the spectra of methane will be carried out as the vibrational and rotational dependence of the parameters describing such effects on the spectra are not well characterized. However, the limit of the Markovian model will need to be tested in confine environment such as hollow core fiber. In those cases, new non-Markovian methodologies will need to be considered.

Publications

See here or at google scholar.

Contact

Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES) (https://squares.ulb.be//),
Université Libre de Bruxelles, CP160/09
50 Av. F.D. Roosevelt, B-1050 Belgium
E-mail


Université Libre de Bruxelles – Faculté des Sciences