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QubitCircuit.resolve_gates() errors on "FREDKIN" gate.

See original GitHub issue

Describe the bug When applying resolve_gates() method to QubitCircuit containing the FREDKIN gate, the following error is produced:

ValueError: Gate RY requires one target

To Reproduce

from qutip.qip.circuit import QubitCircuit
A = QubitCircuit(3)
A.add_gate("FREDKIN", targets=[0, 1], controls=[2])
A.resolve_gates()

It might be a good idea to check this for other gates as well as look into the internal of resolve_gates to clean/modify it a bit.

Note: As requested by @BoxiLi, first mentioned by me in #1318

Issue Analytics

State:
Created 3 years ago
Comments:12 (11 by maintainers)

Top GitHub Comments

1reaction

purva-thakrecommented, Mar 30, 2021

You see, the gate Gate(RY, targets=[0, 1], controls=None) is clearly wrong because RY acts only on one qubits.

Yep ! That’s what I thought as well…for all the single qubit gate outputs with two targets. I knew I was getting an error but was not sure why it was not the same error as both of you. It was because I was using the released version (like you predicted).

I was trying to put off installing from source for as long as I could because I would have to install conda and other dependencies manually. Now, I did get ValuError. Thanks !

0reactions

jakelishmancommented, Apr 13, 2021

Fixed by #1489.

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