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Accueil du site > Séminaires > Séminaires 2014 > Phase transitions of the disordered Bose-Hubbard model within the cavity approach

Mardi 18 mars 2014-14:00

Phase transitions of the disordered Bose-Hubbard model within the cavity approach

Bruno Sciolla (IPHT, Saclay)

par Gabriel LeMarié - 18 mars 2014

We revisit the superfluid-insulator transition in the disordered Bose-Hubbard model within the cavity approach introduced by Ioffe, Mezard [PRL 105, 037001 (2010)]. The method involves a mapping onto a partition function of directed polymers, which has a regime of replica symmetry breaking. We find that due to rare realizations of the disorder, the phase transition is not a second order phase transition for large disorder strengths. In this regime, the superfluid order has an exponential scaling and has properties reminiscent of an infinite disorder fixed point. These results support the idea that disordered quantum criticality in d>1 falls into at least two different classes, second order phase transitions and infinite disorder fixed points, and that the two are realized in the Bose-Hubbard model.

Post-scriptum :

contact : N. Laflorencie