Create error_correction_circuit.py

quantum/circuits/error_correction_circuit.py

@@ -0,0 +1,80 @@
+# error_correction_circuit.py
+import numpy as np
+from qiskit import QuantumCircuit, Aer, execute
+from qiskit.visualization import plot_histogram
+
+def create_error_correction_circuit():
+    """
+    Create a quantum circuit for the 3-qubit bit-flip error correction code.
+    
+    Returns:
+    - QuantumCircuit: The constructed error correction circuit
+    """
+    circuit = QuantumCircuit(5, 3)  # 5 qubits (3 data + 2 ancilla) and 3 classical bits
+
+    # Step 1: Prepare the logical qubit |0> + |1>
+    circuit.h(0)  # Prepare the first qubit in superposition
+
+    # Step 2: Encode the logical qubit into 3 qubits
+    circuit.cx(0, 1)  # |0> -> |00> and |1> -> |11>
+    circuit.cx(0, 2)
+
+    # Simulate a bit-flip error on the second qubit
+    circuit.x(1)  # Introduce an error for demonstration
+
+    # Step 3: Error correction
+    # Measure the first and second qubits into ancilla qubits
+    circuit.cx(1, 3)  # Check qubit 1
+    circuit.cx(2, 4)  # Check qubit 2
+
+    # Step 4: Measure ancilla qubits
+    circuit.measure(3, 0)  # Measure ancilla 1
+    circuit.measure(4, 1)  # Measure ancilla 2
+
+    # Step 5: Apply correction based on measurement results
+    circuit.x(1).c_if(circuit.clbits[0], 1)  # If ancilla 1 is 1, flip qubit 1
+    circuit.x(2).c_if(circuit.clbits[1], 1)  # If ancilla 2 is 1, flip qubit 2
+
+    # Measure the corrected logical qubit
+    circuit.measure(1, 2)  # Measure the first data qubit
+
+    return circuit
+
+def run_error_correction_simulation():
+    """
+    Run the quantum error correction simulation and return the results.
+    
+    Returns:
+    - counts: Measurement results
+    """
+    # Create the error correction circuit
+    circuit = create_error_correction_circuit()
+
+    # Use the Aer's qasm_simulator
+    simulator = Aer.get_backend('qasm_simulator')
+
+    # Execute the circuit on the qasm simulator
+    job = execute(circuit, simulator, shots=1024)
+    result = job.result()
+
+    # Get measurement counts
+    counts = result.get_counts(circuit)
+
+    return counts
+
+def visualize_results(counts):
+    """
+    Visualize the results of the error correction simulation.
+    
+    Parameters:
+    - counts: Measurement results
+    """
+    print("Counts:", counts)
+    plot_histogram(counts).show()
+
+if __name__ == "__main__":
+    # Run the error correction simulation
+    counts = run_error_correction_simulation()
+
+    # Visualize the results
+    visualize_results(counts)