Variational matrix product state approach to quantum impurity models
摘要
We present a unified framework for renormalization group methods, including Wilson's numerical renormalization group (NRG) and White's density-matrix renormalization group (DMRG), within the language of matrix product states. This allows improvements over Wilson's NRG for quantum impurity models, as we illustrate for the one-channel Kondo model. Moreover, we use a variational method for evaluating Green's functions. The proposed method is more flexible in its description of spectral properties at finite frequencies, opening the way to time-dependent, out-of-equilibrium impurity problems. It also substantially improves computational efficiency for one-channel impurity problems, suggesting potentially \emph{linear} scaling of complexity for -channel problems.
引用
@article{arxiv.cond-mat/0504305,
title = {Variational matrix product state approach to quantum impurity models},
author = {A. Weichselbaum and F. Verstraete and U. Schollwöck and J. I. Cirac and Jan von Delft},
journal= {arXiv preprint arXiv:cond-mat/0504305},
year = {2009}
}
备注
revised version with application to Kondo model at large magnetic field (5 pages, 2 figures)