## CONTACTS

• Coordinator
Diego Dalvit
• Quantum Lunch Location:
T-Division Conference Room, TA-3,
Building 123, Room 121

# Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.

Thursday, August 21, 2008
12:30 PM to 2 PM

Speaker: Augusto Smerzi, BEC CNR-INFM and Dipartimento di Fisica, Universita' di Trento, Italy

### TOPIC: Entanglement and Heisenberg Limit in Quantum Interferometry

Abstract
The quantum Fisher information provides a sufficient condition to recognize multi-particle entanglement in a N quibit state. The same criterion gives a necessary and sufficient condition for sub shot-noise phase sensitivity in the estimation of a collective rotation angle $\theta$. The analysis therefore singles out the class of entangled states which are "useful" to overcome classical phase sensitivity in metrology and sensors. We will discuss the creation of such useful entangled states by the non-linear dynamical evolution of a Bose-Einstein condensates trapped in a double-well potential.

Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA