Precision Measurements and tests of fundamental physics with cold molecules

The PhD student will participate in the development of a new-generation molecular clock specifically designed

for precision vibrational spectroscopy of cold molecules in the gas phase. The proposed technology is at the

forefront of cold molecule research and frequency metrology, and opens possibilities for using polyatomic

molecules to perform tests of fundamental physics and explore the limits of the standard model. The apparatus will be used in the first place for measuring the electroweak-interactions-induced tiny energy difference between enantiomers of a chiral molecule, a signature of parity (left-right symmetry) violation, and a sensitive probe of dark matter.

Compared to atoms, molecular systems, owing to their numerous degrees of freedom, offer promising perspectives

for improving tests of fundamental physics and precision measurements in general. Molecules are increasingly

being used internationally for instance to test fundamental symmetries, to measure fundamental constants or their

variation in time, to search for dark matter, ... Many of these experiments can be cast as measurements of

resonance frequencies of molecular transitions highlighting the importance of frequency metrology. They also

require advanced manipulation techniques already standard for atoms: individual states addressing, high detection

rates, long coherence times, cooling of internal and external degrees of freedom.

The PhD student will take an active role in various aspects of the initial developments of the experiment which

constitute major steps in providing such techniques for molecules. She/he will:

- set up the mid-IR quantum cascade laser system at 6.4 μm and 15.5 μm to probe molecular vibrations in these

spectral regions;

- perform first Doppler and sub-Doppler absorption spectroscopy on cold molecules produced at ~1 K in a

novel cold molecule apparatus, with a particular focus on well-chosen promising chiral and achiral organo-metallic

species and polycyclic aromatic hydrocarbons.



Laboratory:
Laboratoire de Physique des Lasers
Field of research:Physics, Mid-IR molecular spectroscopy
Skills :Frequency Metrology Mid-Infrared Optics Vacuum Technology Electronics Molecular Physics Cryogenic Buffer-Gas Cooling, Python coding/Simulation
Knowledge :Quantum Physics, Rovibrational spectroscopy, laser physiqcs, Mid-IR photonics