Compact cold atom systems - prospects for space applications

P.-A. Gominet, Vincent Ménoret, Baptiste Battelier +4 more

Erling Riis, Paul F. Griffin

In this talk, I will outline two stands of our ongoing atomic clock research at the University of Strathclyde, aimed at achieving short-term stabilities surpassing 1e-12 in portable systems. Firstly, I present a cold-atom microwave clock that integrates a grating-MOT within an additively manufactured microwave cavity, enabling a compact and potentially highly stable portable system. The work examines noise minimisation techniques through direct comparison with a cold-atom coherent population trapping (CPT) clock. I will also discuss progress on two-photon rubidium clocks based on MEMS vapour cells with integrated optics. The results highlight their prospects for resilient PNT applications and scalable deployment.

P. Thomann, Mark D. Plimmer, Giovanni Di Domenico +4 more

Rémi Geiger, Guillaume Stern, Patrick Cheinet +7 more

Atom interferometry has hugely benefitted from advances made in cold atom physics over the past twenty years, and ultra-precise quantum sensors are now available for a wide range of applications [1]. In particular, cold atom interferometers have shown excellent performances in the field of acceleration and rotation measurements [2,3], and are foreseen as promising candidates for navigation, geophysics, geo-prospecting and tests of fundamental physics such as the Universality of Free Fall (UFF). In order to carry out a test of the UFF with atoms as test masses, one needs to compare precisely the accelerations of two atoms with different masses as they fall in the Earth’s gravitational field. The sensitivity of atom interferometers scales like the square of the time during which the atoms are in free fall, and on ground this interrogation time is limited by the size of the experimental setup to a fraction of a second. Sending an atom interferometer in space would allow for several seconds of excellent free-fall conditions, and tests of the UFF could be carried out with precisions as low as 10-15 [4]. However, cold atoms experiments rely on complex laser systems, which are needed to cool down and manipulate the atoms, and these systems are usually very sensitive to temperature fluctuations and vibrations. In addition, when operating an inertial sensor, vibrations are a major issue, as they deteriorate the performances of the instrument. This is why cold atom interferometers are usually used in ground based facilities, which provide stable enough environments. In order to carry out airborne or space-borne measurements, one has to design an instrument which is both compact and stable, and such that vibrations induced by the platform will not deteriorate the sensitivity of the sensor. We report on the operation of an atom interferometer on board a plane carrying out parabolic flights (Airbus A300 Zero-G, operated by Novespace). We have constructed a compact and stable laser setup, which is well suited for onboard applications. Our goal is to implement a dual-species Rb-K atom interferometer in order to carry out a test of the UFF in the plane. In this perspective, we are designing a dual-wavelength laser source, which will enable us to cool down and coherently manipulate the quantum states of both atoms. We have successfully tested a preliminary version of the source and obtained a double species magneto-optical trap (MOT).

Wolfgang A. Ertmer, Ernst Maria Rasel, Ch Salomon +3 more

Guglielmo Maria Tino