Phase gate (Qiskit)

Phase gate implementation using Qiskit. The example applies $P(\pi/2) = S$ to $\lvert +\rangle$, rotating it to $\lvert i\rangle = \frac{1}{\sqrt{2}}(\lvert 0\rangle + i\lvert 1\rangle)$.

from qiskit import QuantumCircuit
from qiskit.quantum_info import Statevector
import numpy as np
 
qc = QuantumCircuit(1)
qc.h(0)               # |0> -> |+>
qc.p(np.pi / 2, 0)    # P(pi/2) = S: |+> -> |i>
print(Statevector(qc))
# Statevector([0.70710678+0.j, 0.+0.70710678j], dims=(2,))