PhD student position (M/F) in Experimental Mid-Infrared Photonics and Molecular Physics

Job Description

Thesis Subject

Looking for potential variations of the proton-to-electron mass ratio and other tests of fundamental physics via precision measurements with molecules.

A PhD student position is available to develop cutting-edge experiments aimed at ultra-precise measurements of rovibrational molecular transitions and dedicated to measuring/constraining the potential time variation of the proton-to-electron mass ratio (µ), a fundamental constant of the standard model (SM). Such variations, if detected, would be a signature of physics beyond the SM, providing insights into the nature of dark matter and dark energy. The idea here is to compare molecular spectra of cosmic objects with corresponding laboratory data. The experimental setup is based on quantum cascade lasers (QCLs) locked to optical frequency combs, with traceability to primary frequency standards, a breakthrough technology developed at Laboratoire de Physique des Lasers (LPL), allowing unprecedented spectroscopic precision in the mid-infrared range. This position is funded in the frame of the ANR project Ultiµos (Ultra-precise mid-infrared molecular spectroscopy for testing the stability of µ, the electron-to-proton mass ratio).
The successful applicant will focus on measuring mid-infrared molecular transitions in molecules known for their enhanced sensitivity to changes in µ, such as ammonia and methanol. She/he will set up and stabilize new QCLs in a spectral region hosting particularly relevant transitions. The work will involve achieving sub-Doppler spectroscopic resolution to reach target laboratory frequency accuracies of ~100 Hz needed for comparisons with astronomical observations.

Keywords: Proton-to-electron mass ratio, mid-infrared spectroscopy, frequency metrology, quantum cascade lasers, optical frequency combs, molecular physics, quantum physics, precision measurements, astrophysics, optics & lasers, vacuum, electronics, programming & simulation…

Your Work Environment

The Ultiµos project funded by ANR is a a collaborative effort between Laboratoire Kastler Brossel (LKB) and MONARIS at Sorbonne Université Institut d'Electronique, and Laboratoire de Physique des Lasers (LPL) which seeks to refine current constraints on the possible variation of µ. The activity will take place at LPL, Université Sorbonne Paris Nord, Villetaneuse, within the 'Metrology, Molecules and Fundamental Tests' team (MMFT), but the successful applicant will interact with all partners of the Ultiµos project and will thus have a decisive role to maximise the synergy between them.
The PhD will also be carried out in relationship with national operations such as LabEx FIRST-TF (https://first-tf.com/) and national research infrastructure REFIMEVE (http://www.refimeve.fr/index.php/en/), allowing the applicant to fully integrate with the time-frequency metrology community in France and beyond.

Constraints and risks

Not applicable.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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