Theory of Quantum Sensors

Atom interferometry experiment realised with a Bose-Einstein condensed source split and recombined with laser light beam-splitters and mirrors in a Mach-Zehnder configuration (Quantus project).  
Collective excitations of a Bose-Einstein condensate after a fast transport over a mm distance using an atom chip. R. Corgier et al. New J. Phys. 20, 055002 (2018).

To exploit the full potential of quantum sensors for inertial applications and tests of fundamental physics, careful quantum state engineering schemes of ultra-cold atomic ensembles are required. For most applications, sensors based on atom interferometry promise few orders of magnitude boost in sensitivities compared to state-of-the-art performance if a macroscopic superposition or long drift times of several seconds are realized.

Degenerate quantum gases are prime candidates to rise to both challenges: slow expansion rates and high control of their degrees of freedom. Indeed, their energies can be realistically pushed down to the picokelvin level or below while preserving coherence and being able to precisely shape their quantum properties.

Our research takes advantage of most novel and efficient techniques in the field of quantum gases theory and puts to work highly controllable atom interferometers of metrological significance. Analytical and numerical models are developed relying on optimal control theory protocols together with time-dependent quantum dynamics solvers at their core.

We engage in a direct collaborative effort with a large number of leading experimental groups at the IQ, in Europe and internationally. Our research covers, for example, aspects related to the dynamics of Bose-Einstein condensates manipulated by atom chips or dipole laser traps subject to free fall (fountains, microgravity and space platforms) or in trapped conditions (trapped interferometry, optical cavities, etc.).