Volume 86, Number 1, April 2009
Article Number 17003
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 15 April 2009
EPL, 86 (2009) 17003
DOI: 10.1209/0295-5075/86/17003

Phase transitions, entanglement and quantum noise interferometry in cold atoms

F. Mintert1, 2, 3, A. M. Rey3, 4, I. I. Satija5, 6 and C. W. Clark5, 7

1   Physikalisches Institut, Albert-Ludwigs Universität Freiburg - Hermann-Herder-Str. 3, Freiburg, Germany, EU
2   Department of Physics, Harvard University - 17 Oxford Street, Cambridge, MA, USA
3   Institute for Theoretical Atomic, Molecular and Optical Physics, Harvard University - Cambridge, MA 02138, USA
4   JILA and University of Colorado, Department of Physics, University of Colorado - Boulder, CO 80309, USA
5   National Institute of Standards and Technology - Gaithersburg, MD 20899, USA
6   Department of Physics, George Mason University - Fairfax, VA 22030, USA
7   Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland Gaithersburg, MD 20899, USA

received 22 July 2008; accepted in final form 5 March 2009; published April 2009
published online 15 April 2009

We show that entanglement monotones reveal the pronounced enhancement of entanglement at a quantum phase transition, when they are sensitive to long-range high-order correlations. Such monotones are found to develop a sharp interferometric peak at the critical point, and to exhibit universal scaling. We demonstrate that similar features are shared by noise correlation spectra, and verify that these experimentally accessible quantities encode entanglement information and probe separability. We give a prescription, for mesoscopic scale systems of how to extract the pronounced enhancement of entanglement at a quantum phase transition from limited accessible experimental data.

73.43.Nq - Quantum phase transitions.
42.50.Lc - Quantum fluctuations, quantum noise, and quantum jumps.
03.75.Hh - Static properties of condensates; thermodynamical, statistical, and structural properties.

© EPLA 2009