PhD on a novel active optical clock based on continuous superradiant lasing (M/F)

Job Description

Thesis Subject

Atomic clocks are vital components for many applications in our modern society, such as the operation of GPS and the synchronization of telecommunication networks. Clocks are also used to bolster investigations of fundamental physical phenomena, such as the detection of low-frequency gravitational waves. Recently, a new type of clock has been proposed: the active clock using superradiant lasing. Instead of shining a very stable laser onto ultracold atoms to probe the atom resonance frequency (and thus measure time), the clock would operate by letting the atoms themselves emit light. Much like in a laser, cold atoms would be prepared in an excited state, then placed between two mirrors forming a cavity. The atoms then coherently emit light into the cavity mode. However, unlike a traditional laser, the light frequency will mostly be set by the atoms themselves, and not by the cavity. The light coherence will be set by a collective synchronization of the atomic dipoles with each other – a process called superradiance. Thus, in addition to its significance as a new clock architecture, this system is interesting from a fundamental point of view: it is an example of an open-dissipative system in which correlations of quantum nature may naturally arise.

We have built a prototype for such a cold-atom-based superradiant laser. We want to tackle the unresolved issue of sustaining continuously a superradiant emission, thus harnessing its full potential as a clock. Our design is based on an effusive beam of strontium atoms inside a vacuum chamber, slowed, cooled, guided continuously up to an optical cavity, there to emit light in a superradiant fashion. The construction of the apparatus is completed, and we expect to acquire full control over the atomic velocity distribution in the next few months. The PhD will first be devoted to characterizing the signs of collective interaction between atoms and cavity (i.e., performing cavity-enhanced spectroscopy), and searching for superradiance signals in beat note spectroscopy. Then, the PhD student will investigate the light properties to understand how the emitters synchronize their oscillations, and how the light coherence is related to correlations between all atomic emitters. Our experiment will have the unique capability to explore several distinct superradiant emission regimes, that will be identified through the spectral and correlation properties of the light and of the atoms. In collaboration with metrology experts both from LPL and the QuRIOUS consortium, we will contribute to assessing the metrological interest (i.e., “performance” criteria to act as a clock) of atomic-beam continuous superradiant lasers.

Your Work Environment

The QuRIOUS doctoral network program: This PhD thesis is part of the Marie Sklodowska-Curie doctoral training network QuRIOUS, just recently funded by the European Union. This program will train 15 young scientists to become Europe's future quantum technology leaders. To do so, the network assembles an outstanding and experienced group of scientists and innovators from academia, EU metrology institutes, and industry, with world-class expertise in practical quantum technologies. The new doctoral students will be trained at the universities of Amsterdam, Birmingham, Copenhagen, Toruń, Vienna and Innsbruck, and at the National Center for Scientific Research in France (CNRS – in Paris, Villetaneuse and Besançon) and the National Metrology Institute of Italy; in close collaboration with the industry partners Menlo Systems (Germany), NKT Photonics (Denmark), and QUBIG (Germany). Eleven further associated partners throughout Europe are also involved in the training network.

Constraints and risks

Operation of class IIIB lasers - safety measures.

Compensation and benefits

Compensation

Based on Horizon Europe MSCA-DN program: about 3450€ monthly gross income, plus mobility allowance.

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

The research professions