FacebookTwitterYouTube RSS Feed

Squeezing and entanglement without infinite-range interactions

Event Details

Event Dates: 

Wednesday, February 26, 2014 - 12:30pm

Seminar Location: 

  • JILA Auditorium

Speaker Name(s): 

Michael Foss-Feig

Speaker Affiliation(s): 

Joint Quantum Institute
Seminar Type/Subject

Scientific Seminar Type: 

  • AMO Seminar

Event Details & Abstract: 

It is well known that the application of infinite-range interactions can generate massively entangled states with applications in quantum information and quantum metrology.  Combining recent exact solutions with a controlled perturbative calculation in the inverse system size, we analytically determine the spin-squeezing in Ising models with power-law (1/r^alpha) decaying interactions in D dimensions, thus extending the understanding of spin-squeezing into a much broader and experimentally relevant context.  When interactions are not infinitely long-ranged, the spin squeezing is generally modified by both a lack of translational invariance and by a departure from collective (i.e. within the Dicke manifold) dynamics.  In the large system limit, the former effect destroys squeezing for /any/ power law.  On the other hand, remarkably, the departure from collective dynamics has /no/ effect on squeezing in the large system limit for sufficiently long-range interactions (alpha<2D/3).