Light-Field Controlled Molecular Reactions

ended

It is a long-held dream of physical chemists to not only study, but also fully control chemical reactions. The research aim of this project is to control such reactions using the photon catalysis method. This technique uses a focused, high-power, non-resonant pulsed laser to create a high electric field. This field can interact with the dipole it induces in a molecule. With this so-called dynamic Stark effect, we can alter energy levels and potential energy surfaces of the molecule under study and thereby control the chemistry in the system. Our first goal is to apply this relatively new and state-of-the-art technique to control the chemistry in a small benchmark molecule. This will serve as a proof-of-principle experiment and give us a better understanding of the technique and the molecular mechanisms it affects. Afterwards, our aim is to control conical intersections in relatively large biochemically relevant molecules and to create light-field assisted molecular switches. The experiments will be conducted in a molecular-beam machine. Three lasers will interact with the molecules. The first one will provide the high electric field to control the chemistry, the second laser will excite the molecules and thereby start the chemical reaction, and the third one will ionize the reaction products. The resulting ions and electrons will be recorded using the velocity map imaging technique. We will use state-of-the-art combinations of detection methods to elucidate the controlled chemical reactions in a very high level of detail. The photon catalysis method has the potential to become a relatively easy to implement and general technique that could advance many experiments from the level of understanding to the level of controlling molecular processes. It allows us to manipulate properties of matter at the molecular level and it could become an important tool in the fields of quantum information, molecular nanotechnology, and photopharmacology, for instance.