PennyLaneAI / PennyLaneAI/catalyst
Using both qml.ctrl and qml.adjoint causes named operations to execute as matrix operations
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- Dominant language
- Python
- Stars
- 234
- Forks
- 84
- Avg merge
- 2d 15h
- Merged PRs (30d)
- 66
Description
Running the following circuit:
def small_circ():
op = qml.T(0)
op = qml.adjoint(op)
op = qml.ctrl(op, control=1, control_values=[1])
return qml.state()
using null.qubit as the device executes a matrix operation instead of the named gate. Removing either the adjoint or the controlled makes the gate named again (and applies a T gate with either inverse=True or control_wires having data), but the presence of both makes it a matrix op and not a named op.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the circuit from the issue on the null.qubit device, keeping both qml.adjoint and qml.ctrl applied to qml.T. Trace how the operation is represented after these transforms and compare it with cases where either transform is removed. Done means the combined operation remains a named T operation rather than becoming a matrix operation.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100