Expérimental
Atomic clocks are vital components in modern technologies as well as in fundamental physics experiments. Recently, a new type of clock has been proposed: the “superradiant laser”. Instead of shining a stable laser onto cold atoms to probe their resonance frequency, the clock would operate by letting the atoms themselves emit light. The atoms would be placed in an optical cavity, but unlike a traditional laser, the emission process will rely on a collective synchronization of the atomic dipoles (superradiance), and the light frequency and coherence will mostly depend on the atoms. 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 a cold-atom-based superradiant laser. It relies on a beam of strontium atoms inside a vacuum chamber, guided by laser cooling up to an optical cavity, there to emit light in a superradiant fashion. The intern will be in charge of laser cooling and guiding atoms into the cavity, observing the first signs of collective interaction between the atoms and the light field in the cavity, and ultimately detecting superradiant emission. This work can then be continued into a PhD project, to understand how the emitters synchronize their oscillations, and contribute to assessing the interest of superradiant lasers as clocks.