Delta-kick Squeezing

The DKS pulse is used in a preparation step (a) to focus the atomic matter waves and generate squeezing before injecting the entangled atoms in the actual interferometer (b). A final step of a robust non-linear readout is involving a second DKS pulse (c).

Surpassing the standard quantum limit (SQL) holds the promise of boosting the performance of quantum sensors. In particular, free-fall atom interferometers could benefit from such an improved sensitivity to reach beyond-state-of-the-art resolutions of external forces such as accelerations and rotations. Entanglement-enhanced atom interferometry was, however, limited so far by the vanishing interactions between particles during the free fall of the interferometer.   

In a recent work, scientists from Institute of Quantum Optics of the Leibniz University and from LENS in Florence, including DQ-mat PI Naceur Gaaloul and Mercator fellow Augusto Smerzi, proposed a scheme overcoming this previous limitation by employing a matter-wave lens system that focuses Bose-Einstein condensates and enhances interaction-driven squeezing. This method called « delta-kick squeezing » (DKS) was theoretically investigated in the case of Raman and Bragg linear interferometers leading to a phase sensitivity gain of 30 dB beyond the SQL.

They have published their results in the journal Physical Review Letters.

Original Article:
Delta-Kick Squeezing
Robin Corgier, Naceur Gaaloul, Augusto Smerzi, and Luca Pezzè
Phys. Rev. Lett. 127, 183401