Superfluid-insulator transition of interacting disordered bosons in one dimension
Zoran Ristivojevic
CPHT, Ecole Polytechnique
Lundi 11/02/2013, 14:00
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
Interacting bosons generically form a superfluid state. In the presence of disorder it can get converted into a compressible Bose glass state. We study such transition in one dimension at moderate interaction using bosonization and renormalization group techniques. We derive the two-loop scaling equations and discuss the phase diagram. The correlation functions at the transition are characterized by universal exponents in a finite region around the fixed point. We apply the derived theory to an XXZ spin-1/2 chain in the presence of several types of disorder that do not break the XY symmetry and calculate the complete asymptotic form of the spin-correlation functions at zero temperature at the transition between the liquid and the disordered phase. Apart from a universal power law decay of correlations, we find additional logarithmic corrections due to marginally irrelevant operator of disorder.
Contact : Gregoire MISGUICH


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