Matrix Product Toolkit | Tools / MpEaChangeK

Change the momentum of an EA wavefunction.

Synopsis

mp-ea-change-k [options] <psi-in> <psi-out> -k <momentum>

Brief description

Options

--help

Show help message.

-k, --momentum

Change to mometum to this value (in units of {$\pi$}) (required).

--latticeucsize

Size of the lattice unit cell to use (defaults to the wavefunction attribute LatticeUnitCellSize or 1 if unspecified).

-f, --force

Force overwriting the output file if it already exists.

-v, --verbose

Increase verbosity.

Description

This tool creates a copy of the EA wavefunction psi-in, and creates a copy of it in psi-out with the new momentum specified by the -k option. (If psi-in and psi-out are the same file, then this will simply just change its momentum.) The main use case of this tool is when solving for excited states over a range of momenta, we can use the solution found at some momentum {$k$} as an initial condition at some {$\tilde{k} = k + k'$}, which we can optimise with mp-ea-dmrg?.