N-leg spin-S Heisenberg ladders: A density-matrix renormalization group study

摘要: We investigate the $N$-leg spin-$S$ Heisenberg ladders by using density matrix renormalization group method. present estimates of spin gap ${\ensuremath{\Delta}}_{s}$ and ground-state energy per site ${e}_{\ensuremath{\infty}}^{N}$ in thermodynamic limit for with widths up to six legs $S\ensuremath{\le}\frac{5}{2}$. also estimate ${e}_{\ensuremath{\infty}}^{2\mathrm{D}}$ infinite two-dimensional model. Our results support that semi-integer spins excitation is gapless $N$ odd gapped even, whereas integer nonzero, independent number legs. Those agree well-known conjectures Haldane S\'en\'echal-Sierra chains ladders, respectively. observe edge states odd, similar what happens chains.