The non-Abelian density matrix renormalization group algorithm

Department of Theoretical Physics, Institute of Advanced Studies The Australian National University - Canberra, ACT 0200, Australia

Received: 9 May 2001
Accepted: 7 January 2002

Abstract

We describe here the extension of the density matrix renormalization group algorithm to the case where the Hamiltonian has a non-Abelian global symmetry group. The block states transform as irreducible representations of the non-Abelian group. Since the representations are multi-dimensional, a single block state in the new representation corresponds to multiple states of the original density matrix renormalization group basis. We demonstrate the usefulness of the construction via the one-dimensional Hubbard model as the symmetry group is enlarged from , up to .