Quantum Monte Carlo simulations for disordered Bose systems
Abstract
Interacting bosons in a random potential can be used to model {sup 3}He adsorbed in porous media, universal aspects of the superconductor-insulator transition in disordered films, and vortices in disordered type II superconductors. We study a model of bosons on a 2D square lattice with a random potential of strength V and on-site repulsion U. We first describe the path integral Monte Carlo algorithm used to simulate this system. The 2D quantum problem (at T=0) gets mapped onto a classical problem of strings or directed polymers moving in 3D with each string representing the world line of a boson. We discuss efficient ways of sampling the polymer configurations as well as the permutations between the bosons. We calculate the superfluid density and the excitation spectrum. Using these results we distinguish between a superfluid, a localized or Bose glass'' insulator with gapless excitations and a Mott insulator with a finite gap to excitations (found only at commensurate densities). We discover novel effects arising from the interpaly between V and U and present preliminary results for the phase diagram at incommensurate and commensurate densities.
- Authors:
- Publication Date:
- Research Org.:
- Argonne National Lab., IL (United States)
- Sponsoring Org.:
- USDOE; USDOE, Washington, DC (United States)
- OSTI Identifier:
- 5672077
- Report Number(s):
- ANL/CP-75721; CONF-920292-1
ON: DE92010343
- DOE Contract Number:
- W-31109-ENG-38
- Resource Type:
- Conference
- Resource Relation:
- Conference: Workshop on recent developments in computer simulation studies in condensed matter physics, Athens, GA (United States), 17-21 Feb 1992
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BOSONS; PHASE STUDIES; HELIUM 4; SUPERFLUIDITY; COMPUTERIZED SIMULATION; HAMILTONIANS; MONTE CARLO METHOD; SUPERCONDUCTIVITY; TEMPERATURE ZERO K; TWO-DIMENSIONAL CALCULATIONS; TYPE-II SUPERCONDUCTORS; VORTICES; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; EVEN-EVEN NUCLEI; HELIUM ISOTOPES; ISOTOPES; LIGHT NUCLEI; MATHEMATICAL OPERATORS; NUCLEI; PHYSICAL PROPERTIES; QUANTUM OPERATORS; SIMULATION; STABLE ISOTOPES; SUPERCONDUCTORS; 665420* - Superfluidity- (1992-); 665411 - Basic Superconductivity Studies- (1992-)
Citation Formats
Trivedi, N. Quantum Monte Carlo simulations for disordered Bose systems. United States: N. p., 1992.
Web.
Trivedi, N. Quantum Monte Carlo simulations for disordered Bose systems. United States.
Trivedi, N. 1992.
"Quantum Monte Carlo simulations for disordered Bose systems". United States. https://www.osti.gov/servlets/purl/5672077.
@article{osti_5672077,
title = {Quantum Monte Carlo simulations for disordered Bose systems},
author = {Trivedi, N},
abstractNote = {Interacting bosons in a random potential can be used to model {sup 3}He adsorbed in porous media, universal aspects of the superconductor-insulator transition in disordered films, and vortices in disordered type II superconductors. We study a model of bosons on a 2D square lattice with a random potential of strength V and on-site repulsion U. We first describe the path integral Monte Carlo algorithm used to simulate this system. The 2D quantum problem (at T=0) gets mapped onto a classical problem of strings or directed polymers moving in 3D with each string representing the world line of a boson. We discuss efficient ways of sampling the polymer configurations as well as the permutations between the bosons. We calculate the superfluid density and the excitation spectrum. Using these results we distinguish between a superfluid, a localized or Bose glass'' insulator with gapless excitations and a Mott insulator with a finite gap to excitations (found only at commensurate densities). We discover novel effects arising from the interpaly between V and U and present preliminary results for the phase diagram at incommensurate and commensurate densities.},
doi = {},
url = {https://www.osti.gov/biblio/5672077},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Mar 01 00:00:00 EST 1992},
month = {Sun Mar 01 00:00:00 EST 1992}
}