Fermionic implementation of projected entangled pair states algorithm

We present and implement an efficient variational method to simulate two-dimensional finite-size fermionic quantum systems by fermionic projected entangled pair states. The approach differs from the original one due to the fact that there is no need for an extra string bond for contracting the tensor network. The method is tested on a bilinear fermionic model on a square lattice for sizes up to ten by ten where good relative accuracy is achieved. Qualitatively good results are also obtained for an interacting fermionic system.