In June 10th 1999, the Rubidium BEC1 apparatus produced the first italian Bose-Einstein condensate. We soon focused our activity on the study of a quantum gas of 87Rb bosons in optical lattices, investigating static and dynamic properties and enlightening the role of different kinds of instabilities. The last part of the activity was concentrated on the study of the superfluid to Mott insulator transition (also adding disorder and “quasi-disorder”) and on the physics of low-dimensional bosonic gases, characterized by measuring the excitation spectrum of these systems through inelastic light scattering. The BEC1 experiment retired in 2014 after 15 years of activity. We would like to thank all the people – students, technicians, and researchers – who have contributed to these exciting fifteen years of activity.

Measuring entanglement in optical lattices

Entanglement is a fundamental resource for quantum information processing, occurring naturally in many-body systems at low temperatures. The presence of entanglement and, in particular, its scaling with the size of system partitions underlies the complexity of quantum many-body states. The quantitative estimation of entanglement in many-body systems represents a major challenge, as it requires either full-state tomography, scaling exponentially in the system size, or the assumption of unverified system characteristics such as its Hamiltonian or temperature. Here we adopt recently developed approaches for the determination of rigorous lower entanglement bounds from readily accessible measurements and apply them in an experiment of ultracold interacting bosons in optical lattices of 105 sites. We then study the behaviour of spatial entanglement between the sites when crossing the superfluid-Mott insulator transition and when varying temperature. This constitutes the first rigorous experimental large-scale entanglement quantification in a scalable quantum simulator.

M. Cramer et al.,
Spatial entanglement of bosons in optical lattices
Nat. Commun. 4, 2161 (2013)

Rb people

Former members:
Alain Bernard
Sven Burger
Francesco S. Cataliotti
Jacopo Catani
David Clément
Luigi De Sarlo
Nicole Fabbri
Leonardo Fallani
Marco Fattori
Francesca Ferlaino
Chiara Fort
Vera Guarrera
Massimo Inguscio
Jessica E. Lye
Pasquale Maddaloni
Francesco Marin
Francesco Minardi
Marco Prevedelli
Leonardo Ricci
Sara Rosi
Robert Saers
Guglielmo M. Tino
Richard. van der Stam
Michael Zawada
Collaborations:
Veronica Ahufinger
Ehud Altman
Arturo Bambini
Rodolfo Bonifacio
Tommaso Calarco
Filippo Caruso
Jean-Sebastien Caux
Maria Luisa Chiofalo
Mary Manuela Cola
Ramon Corbalán
Eric A. Cornell
Marcus Cramer
Franco Dalfovo
Jason Ensher
Sebastian D. Huber
Michele Modugno
Simone Montangero
Milosz Panfil
Paolo Pedri
Nicola Piovella
Lev Pitaevskii
Martin B. Plenio
Augusto Smerzi
Sandro Stringari
Mario P. Tosi
Andrea Trombettoni
Diederik S. Wiersma

Rb contacts

For further information and request of material, please contact:

Chiara Fort
(fort@lens.unifi.it)