Density matrix renormalization group algorithm for Bethe lattices of spin-1/2 or spin-1 sites with Heisenberg antiferromagnetic exchange

作者：Kumar Manoranjan^*; Ramasesha S; Soos Zoltan G

来源：Physical Review B, 2012, 85(13): 134415.

DOI：10.1103/PhysRevB.85.134415

A density matrix renormalization group (DMRG) algorithm is presented for the Bethe lattice with connectivity Z = 3 and antiferromagnetic exchange between nearest-neighbor spins s = 1/2 or 1 sites in successive generations g. The algorithm is accurate for s = 1 sites. The ground states are magnetic with spin S(g) = 2(g)s, staggered magnetization that persists for large g %26gt; 20, and short-range spin correlation functions that decrease exponentially. A finite energy gap to S %26gt; S(g) leads to a magnetization plateau in the extended lattice. Closely similar DMRG results for s = 1/2 and 1 are interpreted in terms of an analytical three-site model.

• 出版日期2012-4-6