diff --git a/quantum/circuits/fault_tolerant_circuit.py b/quantum/circuits/fault_tolerant_circuit.py new file mode 100644 index 000000000..a1966e4d3 --- /dev/null +++ b/quantum/circuits/fault_tolerant_circuit.py @@ -0,0 +1,84 @@ +# fault_tolerant_circuit.py +import numpy as np +from qiskit import QuantumCircuit, Aer, execute +from qiskit.visualization import plot_histogram + +def create_fault_tolerant_circuit(): + """ + Create a quantum circuit for the Steane code (7-qubit code). + + Returns: + - QuantumCircuit: The constructed fault-tolerant circuit + """ + circuit = QuantumCircuit(7, 7) # 7 qubits for the Steane code and 7 classical bits for measurement + + # Step 1: Encode the logical qubit |0> into the Steane code + circuit.h(0) # Prepare the logical |+> state + circuit.cx(0, 1) + circuit.cx(0, 2) + circuit.cx(0, 3) + circuit.cx(0, 4) + circuit.cx(0, 5) + circuit.cx(0, 6) + + # Step 2: Simulate a bit-flip error on one of the qubits (for demonstration) + circuit.x(1) # Introduce an error on qubit 1 + + # Step 3: Error detection + # Measure the parity of the first three qubits + circuit.cx(1, 3) + circuit.cx(2, 3) + circuit.measure(3, 0) # Measure parity into classical bit 0 + + # Measure the parity of the last four qubits + circuit.cx(4, 6) + circuit.cx(5, 6) + circuit.measure(6, 1) # Measure parity into classical bit 1 + + # Step 4: Apply correction based on measurement results + circuit.x(1).c_if(circuit.clbits[0], 1) # If parity is 1, flip qubit 1 + circuit.x(2).c_if(circuit.clbits[1], 1) # If parity is 1, flip qubit 2 + + # Step 5: Measure the logical qubit + circuit.measure(range(7), range(7)) # Measure all qubits + + return circuit + +def run_fault_tolerant_simulation(): + """ + Run the fault-tolerant quantum computing simulation and return the results. + + Returns: + - counts: Measurement results + """ + # Create the fault-tolerant circuit + circuit = create_fault_tolerant_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 fault-tolerant simulation. + + Parameters: + - counts: Measurement results + """ + print("Counts:", counts) + plot_histogram(counts).show() + +if __name__ == "__main__": + # Run the fault-tolerant simulation + counts = run_fault_tolerant_simulation() + + # Visualize the results + visualize_results(counts)