The atom interferometer team is interested in interferometry with Matter-wave. In particular, we have been developing atom interferometers with separated arms. These interferometers allow to set up controled perturbations on a single path.
The high sensitivity of quantum interference patterns to these external perturbations can be exploited to measure weak external forces or internal atomic properties with high sensitivity. In particular, our experiments are designed to test the electromagnetic interactions, such as Atom polarisability, Atom-atom interactions, Atom-surface interaction, Atom neutrality. These measurements have applications in fundamental physics and atom metrology. We also study curiosity of quantum mechanics : Topological phase shift, decoherence and dephasing.
Our previous studies on atom interferometry based on a lithium beam can be found here.
Alexandre Gauguet, Tangui Rodzinka, Romain Calviac, Ashley Béguin, Baptiste Allard
We have implemented LMT interferomters up to 200ħk, improving upon the previous record based on a sequence of Bragg pulses. We demonstrate a new methods based on destructive interference processes in the loss channels. This coherent enhancement of Bragg pulses sequences (CEBS) leads to a slow decay in visibility, promising a robust LMT scalability. This method contributes to the development of new tools for quantum sensors, and the development of more ambitious programs planned for the next decade (gravitational wave detectors, space missions, etc.).
We contributed to review a new generation of inertial sensors based on quantum technologies, with applications for space missions. https://doi.org/10.1116/5.0098119
Our proposal "Cold Atom Rubidium Interferometer in Orbit for Quantum Accelerometry - Pathfinder Mission Preparation" (Carioqa-Pmp) has been approved by the EU.
We moved to new labs !!
We moved the BEC interferometer experiment and the atom chip experiment in new labs. Ready for new challenges in this amazing building.
Characterization of an atom interferometer in the quasi-Bragg regime
We present a joint experimental and theoretical study of atom interferometers using BEC manipulated by an optical lattice in the quasi-Bragg regime. The results focus on the diffraction losses and multiport features, which could guide the future studies of atom interferometry.
80 hk LMT Interferometer
We demonstrate a 80 hk LMT interferometer using a sequence of 1st order Bragg pulses. The total duration of the interferometer is 10 ms and the phase sensitivity is 20 mrad shot-to-shot.
Interference pattern with a BEC-interferometer
We got an atom interferometer in the so-called Mach-Zehnder configuration. The beamsplitters and mirror are made with 1st order Bragg diffraction. The fringe visibility is 0.8. The interaction Time between the Bragg pulses is 2ms.
Zeeman state preparation of the BEC
Bose-Einstein condensate (BEC) in a crossed dipole
trap, purified to any one spin projection state by a spin-distillation process applied during the evaporation to BEC.
Rabi flopping between two momentum states
A vertical optical lattice interacts with a BEC to drive first order Bragg diffraction. We have shown Rabi oscillation between momentum states separated by 2hk.
Cold atoms into the new atom chip setup
We have loaded 10 millions atoms in the magnetic trap created with the microscopic chip made in LAAS. This experiment aims at developing efficient ultra-cold atoms sources for onboard atom interferometers.
Response of an interferometers based on sequential light pulses
We calculated the sensitivity function of a LMT-interferometers using sequential accelerating light pulses. The sensitivity to laser phase fluctuations is calculated, and we show that the pulse sequence can be engineered to mitigate the phase noise sensitivity.
HOORAY ! We get our Rubidium BEC
Bose-Einstein condensate of rubidium atoms are obtained using an all-optical trap based on a crossed dipole trap generated by a 50W multi-mode fiber laser (1064 nm) and a 6 W dimple trap at 1560 nm. Pure BEC with more than 40 000 atoms are obtained every 5 seconds.
85Rb and 87Rb Mirror-MOT observed in the new vacuum Chamber !
We load 5 billions cold atoms of rubidium 85 and 87 in a magneto-optical trap near the surface of an atom chip.
Atom interferomtry team and visitors
Sina, Kessi, Maxime, Boris, Alex, Julien, Elise, Julien, Jean-Philippe, Gilles, Jacques.