PennyLaneAI / PennyLaneAI/catalyst
Support `qml.Projector` observable
Open
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enhancement
- Dominant language
- Python
- Stars
- 234
- Forks
- 84
- Avg merge
- 2d 15h
- Merged PRs (30d)
- 66
Description
The Projector observable is not currently supported in Catalyst.
dev = qml.device('lightning.qubit', wires=2)
@qml.qjit
@qml.qnode(dev)
def circuit():
qml.PauliX(0)
return qml.expval(qml.Projector([0, 0], wires=[0, 1]))
>>> circuit()
NotImplementedError: Observable Projector(array([0, 0]), wires=[0, 1]) (of type <class 'pennylane.ops.qubit.observables.BasisStateProjector'>) is not impemented
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
Start from the qml.Projector observable used with qml.expval inside the qml.qjit and lightning.qubit entry points shown in the report. Trace how Catalyst handles supported observables and identify the relevant tests before adding Projector support. Done means the supplied circuit compiles and returns the expected expectation value instead of raising NotImplementedError.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- compilers
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100