Dilution Effects on Two-Dimensional Heisenberg Antiferromagnets with Non-Magnetic Spin-Gapped Ground State
Chitoshi Yasuda, Synge Todo, Munehisa Matsumoto +1 more
Dilution effects on spin-1/2 quantum Heisenberg antiferromagnets with a non-magnetic spin-gapped ground state are studied by means of the quantum Monte Carlo simulation. In the site-diluted system, an antiferromagnetic long-range order (AF-LRO) is induced at an infinitesimal concentration of dilution due to an effective coupling ̃Jmn between induced magnetic moments. In the bond-diluted case, on the other hand, the AF-LRO is not induced up to a certain concentration of dilution due to singlet pairs reformed by an AF coupling ̃J af between the edge spins of the diluted bond through the two-dimensional shortest paths. The competition between ̃Jmn and ̃J af yields peculiar phenomena in the bond-diluted system.
arXiv:cond-mat/0204397•Progress of Theoretical Physics Supplement•Jan 1, 2002•8 citations