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Title: Implementation of the SU(2) Hamiltonian Symmetry for the DMRG Algorithm

Journal Article · · Computer Physics Communications

In the Density Matrix Renormalization Group (DMRG) algorithm (White, 1992, 1993) and Hamiltonian symmetries play an important role. Using symmetries, the matrix representation of the Hamiltonian can be blocked. Diagonalizing each matrix block is more efficient than diagonalizing the original matrix. This paper explains how the the DMRG++ code (Alvarez, 2009) has been extended to handle the non-local SU(2) symmetry in a model independent way. Improvements in CPU times compared to runs with only local symmetries are discussed for the one-orbital Hubbard model, and for a two-orbital Hubbard model for iron-based superconductors. The computational bottleneck of the algorithm and the use of shared memory parallelization are also addressed.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
1044649
Journal Information:
Computer Physics Communications, Vol. 183, Issue 10; ISSN 0010-4655
Country of Publication:
United States
Language:
English