Single-particle versus pair condensation of hard-core bosons with correlated hopping

Journal Article · Wed Nov 01 04:00:00 EST 2006 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.74.174508· OSTI ID:20853863

Schmidt, K P; Dorier, J; Mila, F ^[1]; Laeuchli, A ^[2]

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1. Institute of Theoretical Physics, Ecole Polytechnique Federale de Lausanne, CH 1015 Lausanne (Switzerland)
2. Institut Romand de Recherche Numerique en Physique des Materiaux (IRRMA), CH-1015 Lausanne (Switzerland)

We investigate the consequences of correlated hopping on the ground state properties of hard-core bosons on a square lattice as revealed by extensive exact diagonalizations and quantum Monte Carlo simulations. While for noninteracting hard-core bosons the effective attraction induced by the correlated hopping leads to phase separation at low density, we show that a modest nearest-neighbor repulsion suppresses phase separation, leading to a remarkable low-density pairing phase with no single particle Bose-Einstein condensation but long-range two-particle correlations, signaling a condensation of pairs. We also explain why the unusual properties of the pairing phase are a real challenge for standard one-worm quantum Monte Carlo simulations.

• OSTI ID: 20853863
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 17 Vol. 74; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOSE-EINSTEIN CONDENSATION
BOSONS
COMPUTERIZED SIMULATION
CORRELATIONS
DENSITY
GROUND STATES
MONTE CARLO METHOD