Matrix Product States algorithms in Julia.

This library intends to be a simple but performant implementation of several Matrix Product States (MPS) algorithms in pure Julia. The implemented algortihms so far are the well known 1-site and 2-site DMRG algorithms and Strictly Single-Site DMRG. Functions to build general Matrix Product Operators (MPO) and to extract expectation values from MPS are also available.

Once you have Julia installed you will need the following packages: TensorOperations (for tensor contractions using Einsum notation), HDF5 to store an Mps, and Arpack to locally minimize the energy of a state. You can do this in Julia with:

using Pkg
Pkg.add("HDF5")
Pkg.add("TensorOperations")
Pkg.add("Arpack") # This is difficult to build if Julia was built from source using MKL.

After the packages are installed you have to download this repository (remove the .jl from the directory's name) and write at the top of your Julia script:

push!(LOAD_PATH, "/full/path/to/MPStates/directory")
using MPStates

See here examples of how to use the Mps and Mpo structures and how to find the ground state energy of a Hamiltonian.

WARNING: the API is yet unstable (but slowly converging).