Possibility of direct Mott insulator-to-superfluid transitions in weakly disordered boson systems

@article{Park1999PossibilityOD,
  title={Possibility of direct Mott insulator-to-superfluid transitions in weakly disordered boson systems},
  author={Sung Yong Park and Ji-Woo Lee and Min-Chul Cha and M.Y. Choi and B. J. Kim and Doochul Kim},
  journal={arXiv: Condensed Matter},
  year={1999}
}
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… 
View PDF on arXiv
5 Citations

Figures from this paper

5 Citations

Separation of two regimes in a disordered boson Hubbard model
We study the insulator-to-superfluid transition in a two-dimensional disordered boson Hubbard model at zero temperature for intermediate strength of disorder at commensurate density. Via Monte Carlo…
Mean-field phase diagram of disordered bosons in a lattice at nonzero temperature
Bosons in a periodic lattice with on-site disorder at low but nonzero temperatures are considered within a mean-field theory. The criteria used for the definition of the superfluid, Mott insulator…
Generic incommensurate transition in the two-dimensional boson Hubbard model
The generic transition in the boson Hubbard model, occurring at an incommensurate chemical potential, is studied in the link-current representation using the recently developed directed geometrical…
Cluster Monte Carlo algorithm for the quantum rotor model.
  • F. AletE. Sørensen
  • Physics, Computer Science
    Physical review. E, Statistical, nonlinear, and soft matter physics
  • 2003
TLDR
A highly efficient "worm"-like cluster Monte Carlo algorithm for the quantum rotor model in the link-current representation is proposed and detailed balance is explicitly proved for the algorithm even in the presence of disorder.
Directed geometrical worm algorithm applied to the quantum rotor model.
  • F. AletE. Sørensen
  • Computer Science
    Physical review. E, Statistical, nonlinear, and soft matter physics
  • 2003
TLDR
It is shown how correlation functions C(r,tau) can be straightforwardly obtained from the probability of a worm to reach a site away from its starting point independent of whether or not a directed version of the algorithm is used.

References

SHOWING 1-10 OF 10 REFERENCES
Present address: Department of Theoretical Physics
  • Present address: Department of Theoretical Physics
Phys. Rev. B
  • Phys. Rev. B
  • 1998
Rev. Mod. Phys
  • Rev. Mod. Phys
Phys. Rev. B
  • Phys. Rev. B
Kisker for helpful discussions. This work was supported in part by the Korea Research Foundation made in the program year of 1998 and by the KOSEF through the SRC Program
  • Kisker for helpful discussions. This work was supported in part by the Korea Research Foundation made in the program year of 1998 and by the KOSEF through the SRC Program
Phys. Rev. Lett. Phys. Rev. B
  • Phys. Rev. Lett. Phys. Rev. B
Phys. Rev. Lett. Phys. Rev. B
  • Phys. Rev. Lett. Phys. Rev. B
  • 1106
Phys. Rev. Lett. Phys. Rev. B
  • Phys. Rev. Lett. Phys. Rev. B
Phys. Rev. B Physica A
  • Phys. Rev. B Physica A
Phys. Rev. B Phys. Rev. B
  • Phys. Rev. B Phys. Rev. B