def test_xeb_fidelity_tuple_input():
q0, q1 = cirq.LineQubit.range(2)
circuit = cirq.Circuit(cirq.H(q0), cirq.CNOT(q0, q1))
bitstrings = [0, 1, 2]
f1 = cirq.xeb_fidelity(circuit, bitstrings, (q0, q1))
f2 = cirq.xeb_fidelity(circuit, tuple(bitstrings), (q0, q1))
assert f1 == f2
def test_xeb_fidelity(depolarization, estimator):
prng_state = np.random.get_state()
np.random.seed(0)
fs = []
for _ in range(10):
qubits = cirq.LineQubit.range(5)
circuit = make_random_quantum_circuit(qubits, depth=12)
bitstrings = sample_noisy_bitstrings(circuit,
qubits,
depolarization,
repetitions=5000)
f = cirq.xeb_fidelity(circuit, bitstrings, qubits, estimator=estimator)
amplitudes = cirq.final_wavefunction(circuit)
f2 = cirq.xeb_fidelity(circuit,
bitstrings,
qubits,
amplitudes=amplitudes,
estimator=estimator)
assert np.abs(f - f2) < 1e-6
fs.append(f)
estimated_fidelity = np.mean(fs)
expected_fidelity = 1 - depolarization
assert np.isclose(estimated_fidelity, expected_fidelity, atol=0.04)
np.random.set_state(prng_state)
def test_xeb_fidelity_invalid_bitstrings():
q0, q1 = cirq.LineQubit.range(2)
circuit = cirq.Circuit(cirq.H(q0), cirq.CNOT(q0, q1))
bitstrings = [0, 1, 2, 3, 4]
with pytest.raises(ValueError):
cirq.xeb_fidelity(circuit, bitstrings, (q0, q1))
def test_xeb_fidelity_invalid_qubits():
q0, q1, q2 = cirq.LineQubit.range(3)
circuit = cirq.Circuit(cirq.H(q0), cirq.CNOT(q0, q1))
bitstrings = sample_noisy_bitstrings(circuit, (q0, q1, q2), 0.9, 10)
with pytest.raises(ValueError):
cirq.xeb_fidelity(circuit, bitstrings, (q0, q2))
