1999/01/13 by Sung Yong Park, Park, Sung Yong, Ji-Woo Lee +9
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Condensed Matter (cond-mat) #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Quantum, superfluid, helium dynamics #cond-mat
paper · pdf · doi:10.48550/arxiv.cond-mat/9901116
5 pages, Rev Tex, 6 figures, to appear in Phys. Rev. B
arxiv created 1999/01/13 · openalex publication_date 1999/01/13 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the zero-temperature phase transitions of a two-dimensional disordered boson Hubbard model at incommensurate boson densities. Via matrix diagonalization and quantum Monte Carlo simulations, we construct the phase diagram and evaluate the correlation length exponent nu. In the presence of weak disorder, we obtain nu=0.5 +- 0.1, the same value as that in the pure model, near the tip of a Mott insulator lobe, using the dynamical critical exponent z=2. As the strength of disorder is increased beyond a certain value, however, the value of nu is found to change to 0.9 +- 0.1. This result strongly suggests that there exist direct Mott insulator-to-superfluid transitions around the tip of a Mott insulator lobe in the weak disorder regime.