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arXiv · 1007.1853

Comment on "Feshbach-Einstein Condensates" by V. G. Rousseau and P. J. H. Denteneer

María Eckholt·Tommaso Roscilde
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Abstract

In a recent paper (Phys. Rev. Lett. 102, 015301 (2009), arXiv:0810.3763) Rousseau and Denteneer claim that an unconventional "super-Mott" (SM) phase is realized by bosons trapped in an optical lattice close to a Feshbach resonance with a molecular state. The supposed SM phase, observed via quantum Monte Carlo (QMC) simulations of an atom-molecule Bose-Hubbard model, is an incompressible phase developing spontaneous atomic/molecular supercurrents which are perfectly anticorrelated. Here we show that the identification of this phase is based on a misinterpretation of the estimators of superfluidity in QMC, which break down in the presence of coherent atom/molecule conversion. Our conclusion is that the supposed SM phase is in fact a fully normal insulator.

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María Eckholt, Tommaso Roscilde. 2010-07-12. Comment on "Feshbach-Einstein Condensates" by V. G. Rousseau and P. J. H. Denteneer. https://doi.org/10.1103/physrevlett.105.199603

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