Critically-enhanced spin-nematic squeezing and entanglement in dipolar spinor condensates

TL;DR

This paper investigates how quantum critical effects in dipolar spinor condensates enhance spin-nematic squeezing and entanglement, enabling high-precision quantum metrology near phase transition points.

Contribution

It reveals the role of quantum phase transitions in boosting squeezing and entanglement, providing analytical insights and demonstrating steady-state quantum correlations.

Findings

Quantum phase transitions improve squeezing and QFI.

Heisenberg-limited metrology achievable near critical points.

Steady squeezing and entanglement can be generated dynamically.

Abstract

We study the quantum critical effect enhanced spin-nematic squeezing and quantum Fisher information (QFI) in the spin-1 dipolar atomic Bose-Einstein condensate. We show that the quantum phase transitions can improve the squeezing and QFI in the nearby regime of critical point, and the Heisenberg-limited high-precision metrology can be obtained. The different properties of the ground squeezing and entanglement under even and odd number of atoms are further analyzed, by calculating the exact analytical expressions.We also demonstrate the squeezing and entanglement generated by the spin-mixing dynamics around the phase transition point. It is shown that the steady squeezing and entanglement can be obtained, and the Bogoliubov approximation can well describe the dynamics of spin-nematic squeezed vacuum state.