Quantum Belief Propagation
Strongly Correlated Electrons
2009-11-13 v3 Quantum Physics
Abstract
We present an accurate numerical algorithm, called quantum belief propagation (QBP), for simulation of one-dimensional quantum systems at non-zero temperature. The algorithm exploits the fact that quantum effects are short-range in these systems at non-zero temperature, decaying on a length scale inversely proportional to the temperature. We compare to exact results on a spin-1/2 Heisenberg chain. Even a very modest calculation, requiring diagonalizing only 10-by-10 matrices, reproduces the peak susceptibility with a relative error of less than , while more elaborate calculations further reduce the error.
Cite
@article{arxiv.0706.4094,
title = {Quantum Belief Propagation},
author = {M. B. Hastings},
journal= {arXiv preprint arXiv:0706.4094},
year = {2009}
}