Generation of macroscopic singlet states in atomic ensembles – Niels Bohr Institute - University of Copenhagen

Forward this page to a friend Resize Print kalender-ikon Bookmark and Share

Niels Bohr Institute > Calendar > 2009 > Generation of macrosco...

Generation of macroscopic singlet states in atomic ensembles

We study squeezing of the spin uncertainties by quantum non-demolition (QND) measurement in non-polarized spin ensembles. Unlike the case of polarized ensembles, the QND measurements can be performed with negligible back-action and produce squeezing even in the limit of strong measurement. The generated spin states approach many-body singlet states, and contain a macroscopic number of entangled particles, even when individual spin is large.  We show that the state prepared this way can be detected as entangled by measuring the uncertainties of the collective spin components. We estimate the achievable squeezing of the spin uncertainties for achievable experimental parameters.

We introduce the Gaussian treatment of unpolarized spin states.

 

[1] G. Toth and M.W. Mitchell, arXiv:0901.4110.