def test_proj_to_tp():
# Identity process is trace preserving, so no change
state = vec(kraus2choi(np.eye(2)))
assert np.allclose(state, proj_to_tp(state))
# Bit flip process is trace preserving, so no change
state = vec(kraus2choi(sigma_x))
assert np.allclose(state, proj_to_tp(state))
def test_cptp():
# Identity process is cptp, so no change
state = np.array(kraus2choi(np.eye(2)))
assert np.allclose(state, _constraint_project(state))
# Small perturbation shouldn't change too much
state = np.array([[1.001, 0., 0., .99], [0., 0., 0., 0.],
[0., 0., 0., 0.], [1.004, 0., 0., 1.01]])
assert np.allclose(state, _constraint_project(state), atol=.01)
# Bit flip process is cptp, so no change
state = kraus2choi(sigma_x)
assert np.allclose(state, _constraint_project(state))
def test_single_qubit_y(qvm):
qvm.qam.random_seed = 1
process = Program(RY(pi, 0))
exp_desc = generate_process_tomography_experiment(process)
exp_data = acquire_tomography_data(exp_desc, qvm)
estimate = pgdb_process_estimate(exp_data)
assert np.allclose(estimate.estimate.process_choi_est,
kraus2choi(sigma_y),
atol=.01)
def test_two_qubit_cnot(qvm):
qvm.qam.random_seed = 2
process = Program(CNOT(5, 3))
exp_desc = generate_process_tomography_experiment(process)
exp_data = acquire_tomography_data(exp_desc, qvm, var=.05)
estimate = pgdb_process_estimate(exp_data)
assert np.allclose(estimate.estimate.process_choi_est,
kraus2choi(REVERSE_CNOT_KRAUS),
atol=.05)
def test_two_qubit_identity(qvm):
qvm.qam.random_seed = 2
process = Program(I(1)).inst(I(3))
exp_desc = generate_process_tomography_experiment(process)
exp_data = acquire_tomography_data(exp_desc, qvm, var=.05)
estimate = pgdb_process_estimate(exp_data)
assert np.allclose(estimate.estimate.process_choi_est,
kraus2choi(np.eye(4)),
atol=.06)
def test_single_qubit_rx(qvm):
qvm.qam.random_seed = 1
process = Program(RX(pi / 2, 0))
exp_desc = generate_process_tomography_experiment(process)
exp_data = acquire_tomography_data(exp_desc, qvm, var=.005)
estimate = pgdb_process_estimate(exp_data)
assert np.allclose(estimate.estimate.process_choi_est,
kraus2choi(expm(-1j * pi / 4 * sigma_x)),
atol=.01)
def test_two_qubit_cnot_rx_rz(qvm):
qvm.qam.random_seed = 1
process = Program(CNOT(0, 1)).inst(RX(pi / 2, 0)).inst(RZ(1, 1))
exp_desc = generate_process_tomography_experiment(process)
exp_data = acquire_tomography_data(exp_desc, qvm, var=.05)
estimate = pgdb_process_estimate(exp_data)
rx = np.kron(
np.eye(2),
expm(-1j * pi / 4 * sigma_x),
)
rz = np.kron(expm(-1j / 2 * sigma_z), np.eye(2))
assert np.allclose(estimate.estimate.process_choi_est,
kraus2choi(rz @ rx @ CNOT_KRAUS),
atol=.05)
def test_two_q_pgdb(two_q_tomo_fixture):
qubits, results, u_rand = two_q_tomo_fixture
process_choi_est = pgdb_process_estimate(results, qubits=qubits)
process_choi_true = kraus2choi(u_rand)
np.testing.assert_allclose(process_choi_true, process_choi_est, atol=0.05)
