# p_superop.m

Sided product superoperator in the spherical tensor basis set. Returns superoperators corresponding to right or left multiplication of a density matrix by a user-specified operator.

## Syntax

    A=p_superop(spin_system,opspec,side)


## Arguments

    opspec - Spinach operator specification described in Sections 2.1
and 3.3 of the following paper:

http://dx.doi.org/10.1016/j.jmr.2010.11.008

side   - 'left' or 'right' causes the function to return a product
superoperator corresponding to a product from that side;
'comm' or 'acomm' results in commutation and anticommuta-
tion superoperator respectively.


## Outputs

         A - a three-column array of row indices (first column),
column indices (second column) and values (third column).


## Notes

1. This is a very general function to which direct calls are not usually required - please use the much friendlier operator.m function.
2. The superoperator is returned in XYZ sparse format, which is different from Matlab's CSC format.