Persistent and enhanced spin-nematic squeezing in a spinor Bose-Einstein condensate

We propose a simple scheme to realize the persistent spin-nematic squeezing in a spinor Bose-Einstein condensate by rapidly turning-off the external magnetic field at a time that maximal spin-nematic squeezing occurs. We observe that the optimal spin-nematic squeezing can be maintained in a nearly fixed direction. For a proper initial magnetic field, the optimal squeezing can be obviously enhanced. We further construct a spin-mixing interferometer, where the quantum correlation of the squeezed state (generated by our scheme) is fully utilized in the phase measurement, and show the phase sensitivity of the interferometer has a significant enhancement.

Automated summary

The study proposes a simple scheme to achieve persistent spin-nematic squeezing in a spinor Bose-Einstein condensate by rapidly turning off the external magnetic field at the moment when maximal spin-nematic squeezing occurs. It is observed that the optimal squeezing can be maintained in a nearly fixed direction, with a significant enhancement possible through the use of appropriate initial magnetic fields. Additionally, a spin-mixing interferometer is constructed to utilize the quantum correlation of the squeezed state, resulting in a significantly enhanced phase sensitivity for the interferometer.