TensoredOp's to_matrix() returns a wrong value if coeff is not 1

[y-masaomi]

Environment

• Qiskit Terra version:
  0.22.4
• Python version:
  3.10.4
• Operating system:
  Ubuntu 20.04.5 LTS

What is happening?

TensoredOp's to_matrix() returns a wrong value if coeff is not 1.

How can we reproduce the issue?

Run the following code:

from qiskit.opflow import Plus, Zero
print((0.5 * (Plus ^ Zero)).to_matrix())

Then, the following will be printed:

[0.1767767+0.j 0.       +0.j 0.1767767+0.j 0.       +0.j]

What should happen?

The following should be printed:

[0.35355339+0.j, 0.        +0.j, 0.35355339+0.j, 0.        +0.j]

Any suggestions?

I think this problem is related to #9283.

[Cryoris]

Good catch! Indeed it seems to be the same kind of error as for the ComposedOp, #9404 should fix this.

[y-masaomi]

Thank you for your quick response!