Numerical renormalization group method in weakly coupled quantum spin chains: Comparison with exact diagonalization
We show that numerical quasi-one-dimensional renormalization group allows accurate study of weakly coupled spin chains with modest computational effort. We perform a systematic comparison with exact diagonalization results in two- and three-leg spin ladders with a transverse Hamiltonian that can involve frustration. Due to the variational nature of-the algorithm, the accuracy can be arbitrarily improved enlarging the basis of eigenstates in the transverse direction. We observe that the precision of the algorithm is directly correlated to the binding of the chains. We also show that the method performs especially well in magnetically frustrated systems.
numerical renormalization group methods spin models