IMPS_tools

Matrix Product State algorithms for 1) ground states and 2) elementary excitations in the thermodynamic limit.

1. Implementation of the ground state algorithm (VUMPS) presented in https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.045145 (open access). Available are single-site unit-cell and both sequential and parallel multi-site unit-cell implementations.

2. Implementation of the excitation algorithm (Excitations) presented in https://journals.aps.org/prb/abstract/10.1103/PhysRevB.85.100408 (https://arxiv.org/abs/1103.2286). Available are single-site unit-cell and multi-site unit-cell implementations. For the multisite implementation see https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.235155

When using this code, please cite the following open access articles
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.045145 (VUMPS)
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.85.100408 (excitations)
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.235155 (multi site excitations)

Installation

be sure to add the 'helpers' folder to your Path.