Quantum teleportation algorithm using Qiskit

QuantumTeleportation.py

from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit, execute, Aer
from qiskit.visualization import plot_bloch_multivector
from math import pi

%matplotlib inline

# We need three qubits and two classical bits for the algorithm. 
q =  QuantumRegister(3,"q") 
# We have to define classical registers one by one since
# we are applying the C_if gate later
c1 = ClassicalRegister(1,"c1") 
c2 = ClassicalRegister(1,"c2") 
qc = QuantumCircuit(q,c1,c2)

# Crating the angle pi/4 = 45 degrees 
theta = pi*(1/4)
# Rotate the teleporting qubit
qc.ry(theta,q[2])

backend = Aer.get_backend('statevector_simulator') 
result = execute(qc, backend).result()
psi  = result.get_statevector()

print("States of the three qubits before teleporting")
# Displaying the three qubits in bloch sphere
display(plot_bloch_multivector(psi))

# Creating the bell state
qc.h(q[1])
qc.cx(q[1],q[0])

# CNOT gate - teleporting qubit as the control bit
qc.cx(q[2],q[1])

# Hadamard gate on the teleporting qubit
qc.h(q[2])

qc.barrier()

# Alice measure her qubits
qc.measure(q[2],c2)
qc.measure(q[1],c1)

qc.barrier()

# Applying the classical if 
# If classical bit is set apply the gate
qc.x(q[0]).c_if(c1,1)
qc.z(q[0]).c_if(c2,1)

# draw the circuit
display(qc.draw(output='mpl',reverse_bits=True))

backend = Aer.get_backend('statevector_simulator') 
result = execute(qc, backend).result()
psi  = result.get_statevector()

print("States of the three qubits after teleporting")
# Displaying the three qubits in bloch sphere
display(plot_bloch_multivector(psi))