The iPEPS algorithm, improved: fast full update and gauge fixing

Understand

The infinite Projected Entangled Pair States (iPEPS) algorithm [J.

• Jordan et al, PRL 101, 250602 (2008)] has become a useful tool in the calculation of ground state properties of 2d quantum lattice systems in the thermodynamic limit.
• Despite its many successful implementations, the method has some limitations in its present formulation which hinder its application to some highly-entangled systems.
• The purpose of this paper is to unravel some of these issues, in turn enhancing the stability and efficiency of iPEPS methods.