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Reference : UMR7538-BRULAB-011
Workplace : VILLETANEUSE
Date of publication : Tuesday, November 23, 2021
Type of Contract : FTC Scientist
Contract Period : 24 months
Expected date of employment : 3 January 2022
Proportion of work : Full time
Remuneration : 2744 euros to 3 161 euros (monthly gross salary)
Desired level of education : PhD
Experience required : 1 to 4 years
The post-doctoral fellow will contribute to experiments leading to the realisation of a superradiant laser in the steady state. The system consists of a beam of strontium atoms, excited on a narrow line, passing through an optical cavity. The superradiance phenomenon should ensure continuous emission, which is of great interest as a frequency reference - the building block of an optical atomic clock. The person recruited will join us for i) the construction of the experimental device, ii) a first fundamental study of the operating regimes of this new light source based on strong quantum correlations between atoms; and iii), a characterization of the properties of the light, in connection with several metrology teams, thus clarifying the application prospects of this system. Achieving the continuous regime would be a world first, with a strong impact due to its applicability to frequency metrology.
The post-doctoral fellow will join the Quantum Magnetic Gases group of the Laboratoire de Physique des Lasers. The objective will be to participate in the construction of the new superradiant laser experimental apparatus, and to perform the first scientific studies of the behaviour of this system. The work is at the interface of fundamental physics, with the study of an open quantum system with strong quantum correlations; and of the application to frequency metrology, given the very low spectral sensitivity of this source to perturbations of the optical cavity - in contrast to a usual "laser".
The basic technical tools of this activity are continuous lasers, ultra-high vacuum systems and locking systems. The person recruited and the team will also develop new skills in detection and frequency metrology methods: photon correlation measurements, spectrum measurements, and ultimately comparison with an external frequency reference provided by the LNE-SYRTE metrology laboratory and disseminated by the Refimeve+ network.
Candidates should have a PhD in laser-matter interaction and excellent experimental skills. Expertise in cold atom physics (laser cooling), quantum optics or atomic clocks would be an asset, as well as an interest in N-body quantum physics. The postdoc should also have excellent teamwork skills.
The superradiant laser is a promising system as active clock. Several spectacular achievements have been made in recent years, but they have never been compatible with a steady state. Our device takes advantage of a "moderately" narrow line (7 kHz) and a spectral narrowing phenomenon to achieve a steady state at low experimental complexity, using a cold atomic beam without ever fully trapping the atoms. The approach thus follows a different path from most current projects, which would operate on an extremely narrow line, and require a more complex manipulation of ultra-cold atoms.
The activity will take place in the Laboratoire de Physique des Lasers. The Magnetic Quantum Gases group (http://www-lpl.univ-paris13.fr/gqm/) has developed two experiments on the magnetic properties of large spin atoms. One of these two experiments operates with strontium atoms, whose properties are suitable for the realisation of superradiant lasers. Consequently, the new superradiant laser apparatus will use the same atom, and will benefit from a strong synergy with the existing ultra-cold strontium experiment: duplication of technological solutions, sharing of frequency references, and, on a day-to-day basis, joint participation in scientific discussions to explore all the bridges and analogies between the two systems.
The superradiant laser device has been in the design and construction phase for a little less than a year; today, most of the elements have been purchased (lasers, ultra-high vacuum), a few parts (oven, Zeeman slower) have been built, and the design of key parts (optical cavity) has begun.
Two CNRS researchers and a CNRS research engineer will be involved in the project. The research group also includes three professors or assistant professors, one post-doctoral fellow, and four PhD students involved in the ultra-cold atom devices. Our project is built in close collaboration with Marion Delehaye's team (FEMTO-ST), for the joint development of two superradiant lasers in complementary regimes, as well as with Igor Ferrier Barbut's team (LCF), for the understanding of the fundamental physics of superradiance. Close links with the local metrology teams at LPL (Benoit Darquié) and LNE-SYRTE (Rodolphe Le Targat) allow the development of spectral comparisons.
Project funded by Labex FIRST-TF, SureCo project (Superradiance in Continuous Regime), in collaboration with Marion Delehaye's team (FEMTO-ST, Besançon). Other fundings: DIM SIRTEQ Mi-Lourd project FSTOL (From Superradiance To Lasing), in collaboration with Igor Ferrier-Barbut (Laboratoire Charles Fabry), and ANR CONSULA (Continuous Superradiant Laser), in collaboration with Marion Delehaye.
The first year of the contract will be funded by SureCo, and the second year by CONSULA.
Research team website: http://www-lpl.univ-paris13.fr/gqm/
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