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Supersolids versus phase separation in two-dimensional lattice bosons

Pinaki Sengupta·Leonid P. Pryadko·Fabien Alet·Matthias Troyer·Guido Schmid
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Abstract

We study the nature of the ground state of the strongly-coupled two dimensional extended boson Hubbard model on a square lattice. We demonstrate that strong but finite on-site interaction U along with a comparable nearest-neighbor repulsion V result in a thermodynamically stable supersolid ground state just above half-filling, and that the checker-board crystal is unstable for smaller V, and for any V just below half-filling. The interplay between these two interaction energies results in a rich phase diagram which is studied in detail using quantum Monte Carlo methods.

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Pinaki Sengupta, Leonid P. Pryadko, Fabien Alet, Matthias Troyer, Guido Schmid. 2004-12-14. Supersolids versus phase separation in two-dimensional lattice bosons. https://doi.org/10.1103/physrevlett.94.207202

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