Create basic_circuits.py

quantum/circuits/basic_circuits.py

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+# basic_circuits.py
+import numpy as np
+from qiskit import QuantumCircuit, Aer, execute
+from qiskit.visualization import plot_histogram, plot_bloch_multivector
+from qiskit.quantum_info import Statevector
+
+def create_hadamard_circuit(num_qubits):
+    """
+    Create a quantum circuit with Hadamard gates applied to all qubits.
+    
+    Parameters:
+    - num_qubits: Number of qubits in the circuit
+    
+    Returns:
+    - QuantumCircuit: The constructed quantum circuit
+    """
+    circuit = QuantumCircuit(num_qubits, num_qubits)
+    for qubit in range(num_qubits):
+        circuit.h(qubit)  # Apply Hadamard gate
+    circuit.measure(range(num_qubits), range(num_qubits))  # Measure all qubits
+    return circuit
+
+def create_cnot_circuit(num_qubits):
+    """
+    Create a quantum circuit with a CNOT gate applied between the first two qubits.
+    
+    Parameters:
+    - num_qubits: Number of qubits in the circuit
+    
+    Returns:
+    - QuantumCircuit: The constructed quantum circuit
+    """
+    circuit = QuantumCircuit(num_qubits, num_qubits)
+    if num_qubits > 1:
+        circuit.cx(0, 1)  # Apply CNOT gate
+    circuit.measure(range(num_qubits), range(num_qubits))  # Measure all qubits
+    return circuit
+
+def create_entanglement_circuit():
+    """
+    Create a quantum circuit that generates a Bell state (entangled state).
+    
+    Returns:
+    - QuantumCircuit: The constructed quantum circuit
+    """
+    circuit = QuantumCircuit(2, 2)
+    circuit.h(0)  # Apply Hadamard to the first qubit
+    circuit.cx(0, 1)  # Apply CNOT to create entanglement
+    circuit.measure(range(2), range(2))  # Measure both qubits
+    return circuit
+
+def run_circuit(circuit):
+    """
+    Run the quantum circuit and return the results.
+    
+    Parameters:
+    - circuit: QuantumCircuit object
+    
+    Returns:
+    - counts: Measurement results
+    - statevector: State vector of the quantum system
+    """
+    # 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)
+
+    # Get the state vector for visualization
+    statevector = Statevector.from_dict(counts)
+
+    return counts, statevector
+
+def visualize_results(counts, statevector):
+    """
+    Visualize the results of the quantum circuit simulation.
+    
+    Parameters:
+    - counts: Measurement results
+    - statevector: State vector of the quantum system
+    """
+    print("Counts:", counts)
+    plot_histogram(counts).show()
+    plot_bloch_multivector(statevector).show()
+
+if __name__ == "__main__":
+    # Example usage of the circuit functions
+    num_qubits = 2  # Number of qubits
+
+    # Create and run Hadamard circuit
+    hadamard_circuit = create_hadamard_circuit(num_qubits)
+    counts, statevector = run_circuit(hadamard_circuit)
+    print("Hadamard Circuit Results:")
+    visualize_results(counts, statevector)
+
+    # Create and run CNOT circuit
+    cnot_circuit = create_cnot_circuit(num_qubits)
+    counts, statevector = run_circuit(cnot_circuit)
+    print("CNOT Circuit Results:")
+    visualize_results(counts, statevector)
+
+    # Create and run entanglement circuit
+    entanglement_circuit = create_entanglement_circuit()
+    counts, statevector = run_circuit(entanglement_circuit)
+    print("Entanglement Circuit Results:")
+    visualize_results(counts, statevector)