import inspect
import math
import random
from typing import List, Optional
from braket.circuits import Circuit, Gate, Instruction
from braket.circuits.gates import CNot, H, S, T
[docs]
def random_circuit(
num_qubits: int,
num_gates: int,
gate_set: Optional[List[Gate]] = None,
seed: Optional[int] = None,
) -> Circuit:
"""
Generates a random quantum circuit.
Args:
num_qubits (int): Number of qubits in the circuit.
num_gates (int): Number of instructions (gates) in the circuit.
gate_set (Optional[List[Gate]]): List of basis gates for the random circuit
(default is None).
seed (Optional[int]): Random seed for reproducibility (default is None).
Returns:
Circuit: random quantum circuit.
"""
# Set the seed if provided
if seed is not None:
random.seed(seed)
# Default gate_set (Clifford + T) if gate_set is None
if not gate_set:
gate_set = [CNot, S, T, H]
instructions = []
for _ in range(num_gates):
gate = random.choice(gate_set)
gate_qubits = gate.fixed_qubit_count()
# Select random qubits for the gate
qubits = random.sample(range(num_qubits), gate_qubits)
# Get the constructor's signature to determine required parameters
init_signature = inspect.signature(gate.__init__)
# Calculate the number of parameters (excluding 'self')
num_params = len(init_signature.parameters) - 1
# Generate random parameters for the gate in the range [0, 2*pi]
params = [random.uniform(0, 2 * math.pi) for _ in range(num_params)]
# Create the gate instance
g = gate(*params)
# Add the gate as an instruction
instructions.append(Instruction(g, qubits))
# Create a circuit with the list of instructions
circuit = Circuit().add(instructions)
return circuit