34 research outputs found
Weak first-order superfluid--solid quantum phase transitions
We study superfluid--solid zero-temperature transitions in two-dimensional
lattice boson/spin models by Worm-Algorithm Monte Carlo simulations. We observe
that such transitions are typically first-order with the exception of special
high-symmetry points which require fine tuning in the Hamiltonian parameter
space. We present evidence that the superfluid--checkerboard solid and
superfluid--valence-bond solid transitions at half-integer filling factor are
extremely weak first-order transitions and in small systems they may be
confused with continuous or high-symmetry points.Comment: 4 pages, revtex4, 6 figure