Matrix Product Toolkit | Tools / MpReorderSymmetryOld

This program can be used to change the order of quantum numbers in a symmetry list. This has no effect on the state itself, but the ordering of a symmetry list must be consistent to perform operations on wavefunctions or operators.

Matrix Product Toolkit version HEAD-0.7.4.0 (subversion tree rev 802)
Compiled on Dec 10 2007 at 11:50:43
usage: mp-reorder-symmetry <new-symmetry-list> <psi>

The new-symmetry-list must contain the same names and symmetry types as the symmetry list in psi.

Examples

If a wavefunction psi has a symmetry list of Sz:U(1),N:U(1) but you want to use this with another wavefunction or lattice that has a symmetry list of N:U(1),Sz:U(1), then the symmetry list can be changed with

mp-reorder-symmetry "N:U(1),Sz:U(1)" psi

Notes

It is possible to use this tool to add symmetries to a wavefunction. For example, given a spin chain with symmetry list S:SU(2), we can add a pseudospin quantum number Q (which will be set to zero), by specifying a new symmetry list Q:SU(2),S:SU(2).

It is possible to use this tool to remove symmetries from a wavefunction. For example, given a spin chain with a symmetry list S:U(1), we can remove the symmetries by specifying a new symmetry list Null:Null. NOTE: this will produce strange and incorrect results if you remove a non-abelian symmetry! Always project these down to an abelian symmetry with mp-wigner-eckart first.

MpReorderSymmetryOld

Examples

Notes

See Also