Efficient Matrix Product State Method for periodic boundary conditions

Understand

We introduce an efficient method to calculate the ground state of one-dimensional lattice models with periodic boundary conditions.

• The method works in the representation of Matrix Product States (MPS), related to the Density Matrix Renormalization Group (DMRG) method.
• It improves on a previous approach by Verstraete et al.
• We introduce a factorization procedure for long products of MPS matrices, which reduces the computational effort from m^5 to m^3, where m is the matrix dimension, and m ~ 100 - 1000 in typical cases.