If I act a CNOT gate on quantum circuit:
from qiskit import QuantumCircuit qc = QuantumCircuit(2, 2) qc.cx(0, 1)
it means that qubit_0 is the control qubit, and qubit_1 is the target qubit. And if I switch 0 and 1, it means that qubit_1 is the control qubit, and qubit_0 is the target qubit.
But I remember that the CNOT gate is a one-direction gate, which means that one of the case would be the same as the other one but with some hadamard gates acting before and after it on the real device.
So, what I would like to ask is that:
"How can I specify which is the one that would not act other gates when executing on the real device."
I had also checked for the coupling_map:
and it returns both [0, 1] and [1, 0]
I'm not sure which is the one that won't act other hadamard gates, or is the real devices of IBMQ now support both kinds of CNOT operation?
Or, (I'm guessing) the smaller index would be the control qubit?