Supersolidity, entropy, and frustration: t-t{sup '}-V model of hard-core bosons on the triangular lattice

Journal Article · Mon Oct 01 04:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.76.144420· OSTI ID:21052720

Hassan, S R; Tremblay, A.-M. S. ^[1]; Medici, L de ^[2]

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1. Department de Physique and RQMP, Universite de Sherbrooke, Sherbrooke, Quebec, J1 K 2R1 (Canada)
2. Department of Physics and Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854 (United States)

We study the properties of t-t{sup '}-V model of hard-core bosons on the triangular lattice that can be realized in optical lattices. By mapping to the spin-1/2 XXZ model in a field, we determine the phase diagram of the t-V model where the supersolid characterized by the ordering pattern (x,x,-2x{sup '}) (''ferrimagnetic'' or SS A) is a ground state for chemical potential {mu}>3V. By turning on either temperature or t{sup '} at half filling ({mu}=3V), we find a first order transition from SS A to the elusive supersolid characterized by the (x,-x,0) ordering pattern (''antiferromagnetic'' or SS C). In addition, we find a large region where a superfluid phase becomes a solid upon increasing temperature at fixed chemical potential. This is an analog of the Pomeranchuk effect driven by the large entropic effects associated with geometric frustration on the triangular lattice.

• OSTI ID: 21052720
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 14 Vol. 76; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
AUGMENTATION
BOSONS
ENTROPY
GROUND STATES
PHASE DIAGRAMS
SOLIDS
SPIN
SUPERFLUIDITY