arXiv:cond-mat/9503107 · Physical Review Letters
Thermodynamic Limit of Density Matrix Renormalization
Stellan S. Ostlund, Stefan Rommer
Abstract
The density matrix renormalization group discovered by White is investigated. In the case where renormalization eventually converges to a fixed point we show that quantum states in the thermodynamic limit with periodic boundary conditions can be simply represented by a ``matrix product ground state'' with a natural description of Bloch states of elementary excitations. We then observe that these states can be rederived through a simple variational ansatz making no reference to a renormalization construction. The method is tested on the spin-1 Heisenberg model.