Initialisation of qubits passed to the backends about pytket-docs HOT 3 CLOSED

On the AerStateBackend (and most others), the qubits are automatically initialized to the all-zero state. To initialize to another computational basis state just add X gates as appropriate to the start of your circuit. In your example you'd need to prepend an X on the second qubit.

from pytket-docs.

I meant something such as:

qc = QuantumCircuit(2)
initial_state = [0,1]  # Specify your initial state here
initial_state = [1/np.sqrt(2), 1/np.sqrt(2)]  # Define state |q_0>
initializer = Initialize(initial_state)  # create the gate
initializer.label = "init"  # give it a label (this is the step that avoids the bug)
qc.append(initializer, [0])  # append it to circuit (replace 'q' with the qubit index)

qc.h(0)
qc.cx(0, 1)

from pytket-docs.

Pytket doesn't have a built-in method for arbitrary state preparation. Your best bet may be to use the qiskit method for that, decompose the qiskit circuit to gates, and then convert to pytket using the pytket-qiskit extension module.

from pytket-docs.