Delta-kick Squeezing

TL;DR

This paper proposes a novel delta-kick squeezing technique to enhance atom interferometry sensitivity beyond the standard quantum limit by amplifying interactions and employing non-linear readout schemes, achieving over 30 dB improvement.

Contribution

It introduces delta-kick squeezing (DKS) to significantly increase entanglement and measurement precision in BEC-based atom interferometers.

Findings

Over 30 dB sensitivity gain predicted beyond SQL.

Enhanced entanglement via rapid trap focusing during preparation.

Robust non-linear readout scheme improves measurement accuracy.

Abstract

We explore the possibility to overcome the standard quantum limit (SQL) in a free-fall atom interferometer using a Bose-Einstein condensate (BEC) in either of the two relevant cases of Bragg or Raman scattering light pulses. The generation of entanglement in the BEC is dramatically enhanced by amplifying the atom-atom interactions via the rapid action of an external trap focusing the matter-waves to significantly increase the atomic densities during a preparation stage -- a technique we refer to as delta-kick squeezing (DKS). The action of a second DKS operation at the end of the interferometry sequence allows to implement a non-linear readout scheme making the sub-SQL sensitivity highly robust against imperfect atom counting detection. We predict more than 30 dB of sensitivity gain beyond the SQL for the variance, assuming realistic parameters and $10^6$ atoms.