Two-Site Shift Product Wave Function Renormalization Group Method Applied to Quantum Systems

Abstract

We report a means of wave function estimation for the density matrix renormalization group (DMRG) method applied to quantum systems, which has two-site modulation, when the system size extension is necessary in both the finite and infinite algorithms. The estimation is performed by renormalization group (RG) transformation applied to the ground-state wave function, which is represented by a matrix product. This RG scheme is known as the product wave function renormalization group (PWFRG) method. In order to treat two-site modulation, the operation of the RG transformation is shifted by two lattice sites. It turns out that this two-site shift algorithm enables better wave function estimation in the thermodynamic limit, than the previously known PWFRG algorithm.