Generalization of the singlet sector valence bond loop algorithm to antiferromagnetic ground states with total spin S_tot=1/2

2010/06/14 by Argha Banerjee, Kedar Damle
Physics and Astronomy · #cond-mat.str-el

paper · pdf · doi:10.1088/1742-5468/2010/08/p08017

published as J. Stat. Mech. (2010) P08017 · 6 pages, 6 figures

arxiv created 2010/06/14 · arxiv updated 2010/09/10

Abstract

We develop a generalization of the singlet sector valence bond basis projection algorithm of Sandvik, Beach, and Evertz (A. W. Sandvik, Phys. Rev. Lett. 95, 207203 (2005); K. S. D. Beach and A. W. Sandvik, Nucl. Phys. B750, 142 (2006); A. W. Sandvik and H. G. Evertz, arXiv:0807.0682, unpublished.) to cases in which the ground state of an antiferromagnetic Hamiltonian has total spin S_tot = 1/2 in a finite size system. We explain how various ground state expectation values may be calculated by generalizations of the estimators developed in the singlet case, and illustrate the power of the method by calculating the ground state spin texture and bond energies in a L × L Heisenberg antiferromagnet with L odd and free boundaries.

Citations

• Loop updates for variational and projector quantum Monte Carlo simulations in the valence-bond basis