Split spin-squeezed Bose–Einstein condensates

Abstract

We investigate and model a method for producing entanglement between two spatially separated Bose-Einstein condensates (BECs). In our approach, a spin-polarized BEC is squeezed using a (S z ) 2 interaction, then are split into two separate clouds. After the split, we consider that the particle number in each cloud collapses to a fixed number. We show that this procedure is equivalent to applying an interaction corresponding to squeezing each cloud individually plus an entangling operation. We analyze the system's inter-well entanglement properties and show that it can be detected using correlation-based entanglement criteria. The nature of the states is illustrated by Wigner functions and have the form of a correlated squeezed state. The conditional Wigner function shows high degrees of non-classicality for dimensionless squeezing times beyond N 1 , where N is the number of particles per BEC.

Multiparameter squeezing for optimal quantum enhancements in sensor networks

“…The analysis of the squeezing matrix reveals optimal strategies for the design and analysis of atomic and photonic experiments where Gaussian states still represent the best-controlled and most efficiently generated class of states for metrology. Metrological multiparameter squeezing thus lays the foundation for the development of atomic clocks and electromagnetic field sensors, enhanced by non-local quantum correlations in atomic ensembles with spatially distributed and accessible entanglement 47 – 49 , 65 – 69 . Furthermore, optical systems provide an established platform with access to entangled multimode photonic quantum states 50 , 51 , 70 that can be combined with squeezing 71 , 72 .…”

Overview of the Phase Space Formulation of Quantum Mechanics with Application to Quantum Technologies

“…There are further ways to view phase space for bipartite entanglement, for instance the approach in works such as ref. [145] consider bipartite entanglement between two states that have larger Hilbert space, demonstrating the entanglement between two Bose–Einstein condensates. In ref.…”

Two-axis two-spin squeezed states

“…This can then be converted to the 2A2S Hamiltonian using a split-squeezing approach such as that given in Refs. [39,54]. An alternative procedure is to generate the same correlations using optical interference methods [21,40].…”

“…From (C8), and using θ = π/2, φ = π/2 in Eq. (C1), we obtain the form (39), where we used the fact that e iS z π/2 |k (y) = (−1) k |N − k (y) .…”

“…[33,34] where it was found that a complex structure of entanglement is present, with a time dependence showing fractal characteristics. Methods to generate this state have been examined in numerous works [33][34][35][36][37][38][39]. Procedures to generate other types of entangled states have also been studied [40,41].…”