Controlled U gate with multiple control qubits

Question

How do I implement a 3xControlled U gate with different control states in Qiskit?

The standard circuit.cu() funktion does not implement multiple control qubits in this way but just creates sequential U gates.

I have seen this post on StackExchange but don't really know how to translate it into different control states and would still prefer an implementation without additional helper qubits since I try to rebuild this paper.

score 1 · Accepted Answer · answered Feb 09 '23 at 13:47

1

In qiskit you have the ControlledGate class:

https://qiskit.org/documentation/stubs/qiskit.circuit.ControlledGate.html

In order to have different control states, just prepend an $X$ gate where necessary.

answered Feb 09 '23 at 13:47

Michele Amoretti

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Thanks! With that I found my solution in: c3u_gate = UGate(0.1,0,0).control(3, ctrl_state="100") – QuantumAudit Feb 09 '23 at 13:55

Controlled U gate with multiple control qubits

1 Answers1