Matrix Product Toolkit | Tools / MpEaCreate

Create an EA wavefunction from a momentum superposition of an operator acting on an infinite wavefunction

Synopsis

mp-ea-create [options] <operator> <psi> [psi-right] -o <psi-out>

Brief description

Options

--help

Show help message.

-k, --momentum

The momentum of the output EA wavefunction (default 0).

--latticeucsize

Override the lattice unit cell (if unspecified, use the unit cell size of the operator lattice).

-o, --output

Output filename (required).

--streaming

Store the left and right semi-infinite boundaries by references to the input files.

--no-streaming

Store the left and right semi-infinite boundaries by writing them to the output file (default).

-f, --force

Force overwriting the output file if it already exists.

-v, --verbose

Increase verbosity.

Description

This tools creates an EA wavefunction by applying a momentum superposition of a finite operator {$\hat{O}_n$} to an infinite wavefunction {$|\Psi\rangle$}, i.e. {$$|\Phi\rangle = \sum_n \mathrm{e}^{\mathrm{i}kn} \hat{O}_n |\Psi\rangle.$$}

At the moment, this tool is very primitive: it only supports single-site operators and boundary wavefunctions with single-site unit cells.

Notes

The output wavefunction isn’t guaranteed to be normalised. If you require a specific normalisation, you can calculate the norm after applying the operator, then use mp-ea-create with the operator scaled by one divided by the norm.
You can optionally specify the right boundary with psi-right: this must be the same wavefunction as the left boundary, but in right canonical form, if you want to stream the boundaries instead of saving them into the output file. This option cannot be used to generate topologically nontrivial excitations.