Hilbert space kronecker product ignores dimension

[nwittler]

Describe the bug

Using

c3/c3/utils/qt_utils.py

Line 68 in 2b4625f

def hilbert_space_kron(op, indx, dims):

the dimension of the target subspace is ignored.

To Reproduce

hilbert_space_kron(PAULIS["Z"], 1, dims=[3, 3]) has dimension 6, because PAULIS["Z"] has dimension 2 and is kroneckerd with an identity of dim 3.

Expected behavior

The dimensions given in dims=[3, 3] should be respected to result in final dimension 9. The given operator should be extended to fit.

Environment

• OS: Pop OS Linux
• Python 3.8.8
• c3-toolset Version 1.2.2