27 citations · 70 across the 7 of their papers we have counts for
5 papers · 1 filter
Simulating `Complex' Problems with Quantum Monte Carlo
Lizeng Zhang, Geoff Canright, Ted Barnes
We present a new quantum Monte Carlo algorithm suitable for generically complex problems, such as systems coupled to external magnetic fields or anyons in two spatial dimensions. W…
Ground State and Excitations of Disordered Boson Systems
Michael Ma, Pornthep Nisamaneephong, Lizeng Zhang
After an introduction to the dirty bosons problem, we present a gaussian theory for the ground state and excitations. This approach is physically equivalent to the Bogoliubov appro…
A Gaussian Theory of Superfluid--Bose-Glass Phase Transition
P Nisamaneephong, L. Zhang, M. Ma
We show that gaussian quantum fluctuations, even if infinitesimal, are sufficient to destroy the superfluidity of a disordered boson system in 1D and 2D. The critical disorder is t…
Critical Exponents for Three-Dimensional Superfluid--Bose-Glass Phase Transition
Lizeng Zhang, Xiao-Qian Wang
The critical phenomenon of the zero temperature superfluid--Bose-glass phase transition for hard-core bosons on a three-dimensional disordered lattice is studied using a quantum re…
Disordered Boson Systems: A Perturbative Study
Lizeng Zhang
A hard-core disordered boson system is mapped onto a quantum spin 1/2 XY-model with transverse random fields. It is then generalized to a system of spins with an arbitrary magnitud…