title: Quantum critical dynamics simulation of dirty boson systems.
abstract: Recently, the scaling result z=d for the dynamic critical exponent at the Bose glass to superfluid quantum phase transition has been questioned both on theoretical and numerical grounds. This motivates a careful evaluation of the critical exponents in order to determine the actual value of z. We study a model of quantum bosons at T=0 with disorder in 2D using highly effective worm Monte Carlo simulations. Our data analysis is based on a finite-size scaling approach to determine the scaling of the quantum correlation time from simulation data for boson world lines. The resulting critical exponents are z=1.8±0.05, ν=1.15±0.03, and η=-0.3±0.1, hence suggesting that z=2 is not satisfied.
authors.affiliation: Department of Theoretical Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden.
authors.forename: Hannes
authors.initials: H
authors.lastname: Meier
authors.forename: Mats
authors.initials: M
authors.lastname: Wallin