Multilevel Holstein-Primakoff approximation and its application to atomic spin squeezing and ensemble quantum memories

Journal Article · Mon Mar 15 04:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.032314· OSTI ID:21408393

Kurucz, Z; Moelmer, K ^[1]

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1. Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)

We show that an ensemble of identical d-level atoms can be efficiently described by d-1 collective oscillator degrees of freedom in the vicinity of a product state with all atoms in the same, but otherwise arbitrary single-particle state. We apply our description to two different kinds of spin squeezing: (i) when each spin-F atom is individually squeezed without creating interatomic entanglement and (ii) when a particular collective atomic oscillator mode is squeezed via quantum nondemolition (QND) measurement and feedback. When combined in sequence, the order of the two methods is relevant in the final degree of squeezing. We also discuss the role of the two kinds of squeezing when multisublevel atoms are used as quantum memories for light.

• OSTI ID: 21408393
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 81; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
APPROXIMATIONS
ATOMS
CALCULATION METHODS
DEGREES OF FREEDOM
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
FEEDBACK
OSCILLATORS
PARTICLE PROPERTIES
PARTICLES
QUANTUM ENTANGLEMENT
RADIATIONS
SPIN
VISIBLE RADIATION