quantum_teleportation.py

quantum/quantum_teleportation.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+"""
+Build quantum teleportation circuit using three quantum bits
+and 1 classical bit. The main idea is to send one qubit from
+Alice to Bob using the entanglement properties. This experiment
+run in IBM Q simulator with 1000 shots.
+.
+References:
+https://en.wikipedia.org/wiki/Quantum_teleportation
+https://qiskit.org/textbook/ch-algorithms/teleportation.html
+"""
+
+import numpy as np
+import qiskit
+from qiskit import Aer, ClassicalRegister, QuantumCircuit, QuantumRegister, execute
+
+
+def quantum_teleportation(
+    theta: float = np.pi / 2, phi: float = np.pi / 2, lam: float = np.pi / 2
+) -> qiskit.result.counts.Counts:
+
+    """
+    # >>> quantum_teleportation()
+    #{'00': 500, '11': 500} # ideally
+    #      ┌─────────────────┐          ┌───┐
+    #qr_0: ┤  U(π/2,π/2,π/2) ├───────■──┤ H ├─■─────────
+    #      └──────┬───┬──────┘     ┌─┴─┐└───┘ │
+    #qr_1: ───────┤ H ├─────────■──┤ X ├──────┼───■─────
+    #             └───┘       ┌─┴─┐└───┘      │ ┌─┴─┐┌─┐
+    #qr_2: ───────────────────┤ X ├───────────■─┤ X ├┤M├
+    #                         └───┘             └───┘└╥┘
+    #cr: 1/═══════════════════════════════════════════╩═
+    Args:
+        theta (float): Single qubit rotation U Gate theta parameter. Default to np.pi/2
+        phi (float): Single qubit rotation U Gate phi parameter. Default to np.pi/2
+        lam (float): Single qubit rotation U Gate lam parameter. Default to np.pi/2
+    Returns:
+        qiskit.result.counts.Counts: Teleported qubit counts.
+    """
+
+    qr = QuantumRegister(3, "qr")  # Define the number of quantum bits
+    cr = ClassicalRegister(1, "cr")  # Define the number of classical bits
+
+    quantum_circuit = QuantumCircuit(qr, cr)  # Define the quantum circuit.
+
+    # Build the circuit
+    quantum_circuit.u(theta, phi, lam, 0)  # Quantum State to teleport
+    quantum_circuit.h(1)  # add hadamard gate
+    quantum_circuit.cx(
+        1, 2
+    )  # add control gate with qubit 1 as control and 2 as target.
+    quantum_circuit.cx(0, 1)
+    quantum_circuit.h(0)
+    quantum_circuit.cz(0, 2)  # add control z gate.
+    quantum_circuit.cx(1, 2)
+
+    quantum_circuit.measure([2], [0])  # measure the qubit.
+
+    # Simulate the circuit using qasm simulator
+    backend = Aer.get_backend("qasm_simulator")
+    job = execute(quantum_circuit, backend, shots=1000)
+
+    return job.result().get_counts(quantum_circuit)
+
+
+if __name__ == "__main__":
+    print(
+        "Total count for teleported state is: "
+        f"{quantum_teleportation(np.pi/2, np.pi/2, np.pi/2)}"
+    )