Quantum liquid of repulsively bound pairs of particles in a lattice

Journal Article · Sat Sep 15 00:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.033606· OSTI ID:21020556

Petrosyan, David ^[1]; Schmidt, Bernd; Anglin, James R; Fleischhauer, Michael ^[2]

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1. Institute of Electronic Structure and Laser, FORTH, 71110 Heraklion, Crete (Greece)
2. Fachbereich Physik, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany)

Repulsively interacting particles in a periodic potential can form bound composite objects, whose dissociation is suppressed by a band gap. Nearly pure samples of such repulsively bound pairs of cold atoms--'dimers'--have recently been prepared by Winkler et al. [Nature (London) 441, 853 (2006)]. We here derive an effective Hamiltonian for a lattice loaded with dimers only and discuss its implications for the many-body dynamics of the system. We find that the dimer-dimer interaction includes strong on-site repulsion and nearest-neighbor attraction which always dominates over the dimer kinetic energy at low temperatures. The dimers then form incompressible, minimal-surface 'droplets' of a quantum lattice liquid. For low lattice filling, the effective Hamiltonian can be mapped onto the spin-1/2 XXZ model with fixed total magnetization which exhibits a first-order phase transition from the droplet to a gas phase. This opens the door to studying first-order phase transitions using highly controllable ultracold atoms.

• OSTI ID: 21020556
• Journal Information: Physical Review. A, Vol. 76, Issue 3; Other Information: DOI: 10.1103/PhysRevA.76.033606; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMS
DIMERS
DISSOCIATION
DROPLETS
HAMILTONIANS
HUBBARD MODEL
INTERACTIONS
KINETIC ENERGY
LATTICE FIELD THEORY
LIQUIDS
MAGNETIZATION
MANY-BODY PROBLEM
PERIODICITY
PHASE TRANSFORMATIONS
POTENTIALS
SPIN
SURFACES
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0065-0273 K