Finite-Temperature Auxiliary-Field Quantum Monte Carlo for Bose-Fermi Mixtures
Abstract
We present a quantum Monte Carlo (QMC) technique for calculating the exact finite-temperature properties of Bose-Fermi mixtures. The Bose-Fermi Auxiliary-Field Quantum Monte Carlo (BF-AFQMC) algorithm combines two methods, a finite-temperature AFQMC algorithm for bosons and a variant of the standard AFQMC algorithm for fermions, into one algorithm for mixtures. We demonstrate the accuracy of our method by comparing its results for the Bose-Hubbard and Bose-Fermi-Hubbard models against those produced using exact diagonalization for small systems. Comparisons are also made with mean-field theory and the worm algorithm for larger systems. As is the case with most fermion Hamiltonians, a sign or phase problem is present in BF-AFQMC. We discuss the nature of these problems in this framework and describe how they can be controlled with well-studied approximations to expand BF-AFQMC's reach. The new algorithm can serve as an essential tool for answering many unresolved questions about many-body physics in mixed Bose-Fermi systems.
Keywords
Cite
@article{arxiv.1209.0186,
title = {Finite-Temperature Auxiliary-Field Quantum Monte Carlo for Bose-Fermi Mixtures},
author = {Brenda M. Rubenstein and Shiwei Zhang and David R. Reichman},
journal= {arXiv preprint arXiv:1209.0186},
year = {2012}
}
Comments
19 pages, 6 figures