Liquid-solid transitions in the three-body hard-core model
Laboratoire de Physique Statistique, École Normale Supérieure/PSL Research University, UPMC, Université Paris Diderot, CNRS - 24 rue Lhomond, 75005 Paris, France
Received: 9 October 2014
Accepted: 12 January 2015
We determine the phase diagram for a generalisation of two- and three-dimensional hard spheres: a classical system with three-body interactions realised as a hard cut-off on the mean-square distance for each triplet of particles. Quantum versions of this model are important in the context of the unitary Bose gas, which is currently under close theoretical and experimental scrutiny. In two dimensions, the three-body hard-core model possesses a conventional atomic liquid phase and a peculiar solid phase formed by dimers. These dimers interact effectively as hard disks. In three dimensions, the solid phase consists of isolated atoms that arrange in a simple-hexagonal lattice.
PACS: 05.20.Jj – Statistical mechanics of classical fluids / 64.70.dj – Melting of specific substances
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