Superfluid-insulator and roughening transitions in domain walls

S Söyler
Capogrosso-Sansone
Nikolai Prokof'ev, University of Massachusetts - Amherst
Boris Svistunov, University of Massachusetts - Amherst

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This is the pre-published version harvested from ArXiv. The published version is located at http://pra.aps.org/abstract/PRA/v76/i4/e043628

Abstract

We have performed quantum Monte Carlo simulations to investigate the superfluid behavior of one- and two-dimensional interfaces separating checkerboard solid domains. The system is described by the hard-core Bose-Hubbard Hamiltonian with nearest-neighbor interaction. In accordance with Burovski et al. [Phys. Rev. Lett. 94, 165301 (2005)] we find that (i) the interface remains superfluid in a wide range of interaction strength before it undergoes a superfluid-insulator transition; (ii) in one dimension, the transition is of the Kosterlitz-Thouless type and is accompanied by the roughening transition, driven by proliferation of charge-1∕2 quasiparticles; (iii) in two dimensions, the transition belongs to the three-dimensional U(1) universality class and the interface remains smooth. Similar phenomena are expected for domain walls in quantum antiferromagnets.