Entanglement and extreme spin squeezing for a fluctuating number of indistinguishable particles
Authors: Hyllus P., Pezzé L., Smerzi A., Tóth G.
Autors Affiliation: Department of Theoretical Physics, University of the Basque Country UPV/EHU, P.O. Box 644, E-48080 Bilbao, Spain;
INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Italy;
INO-CNR and LENS, Largo Enrico Fermi 6, I-50125 Firenze, Italy;
IKERBASQUE, Basque Foundation for Science, E-48011 Bilbao, Spain;
Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary
Abstract: We extend the criteria for k-particle entanglement from the spin-squeezing parameter presented in Sorensen andMolmer [Phys. Rev. Lett. 86, 4431 (2001)] to systems with a fluctuating number of particles. We also discuss how other spin-squeezing inequalities can be generalized to this situation. Further, we show how, by employing additional degrees of freedom, it is possible to extend the bounds to the case when the individual particles cannot be addressed. As a by-product, this allows us to show that in spin-squeezing experiments with cold gases the particles are typically distinguishable in practice. Our results justify the application of the Sorensen-Molmer bounds in recent experiments on spin squeezing in Bose-Einstein condensates.
Journal/Review: PHYSICAL REVIEW A
Volume: 86 (1) Pages from: 012337 to: 012337
More Information: P.H. thanks M. W. Mitchell, K. Molmer, M. Oberthaler, F. Piazza, and J. Siewert for inspiring discussions. P.H. and G.T. acknowledge financial support of ERC Starting Grant No. GEDENTQOPT and EU Grant No. CHIST-ERA QUASAR. G.T. thanks the MICINN (Project No. FIS2009-12773-C02-02), the Basque Government (Project No. IT4720-10), and the National Research Fund of Hungary OTKA (Contract No. K83858). L.P. acknowledges financial support by MIUR through FIRB Project No. RBFR08H058.DOI: 10.1103/PhysRevA.86.012337Citations: 29data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2019-09-15References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here