def test_measurement_collapse(index):
"""
Test if correct state is created after measurement using the example of
the Bell state
"""
state_00 = tensor(basis(2, 0), basis(2, 0))
state_11 = tensor(basis(2, 1), basis(2, 1))
bell_state = (state_00 + state_11) / sqrt(2)
M = Measurement("BM", targets=[index])
states, probabilities = M.measurement_comp_basis(bell_state)
np.testing.assert_allclose(probabilities, [0.5, 0.5])
for i, state in enumerate(states):
if i == 0:
Mprime = Measurement("00", targets=[1 - index])
states_00, probability_00 = Mprime.measurement_comp_basis(state)
assert probability_00[0] == 1
assert states_00[1] is None
else:
Mprime = Measurement("11", targets=[1 - index])
states_11, probability_11 = Mprime.measurement_comp_basis(state)
assert probability_11[1] == 1
assert states_11[0] is None
def test_wstate(self):
filename = "w-state.qasm"
filepath = Path(__file__).parent / 'qasm_files' / filename
qc = read_qasm(filepath)
rand_state = rand_ket(2)
state = tensor(tensor(basis(2, 0), basis(2, 0), basis(2, 0)),
rand_state)
fourth = Measurement("test_rand", targets=[3])
_, probs_initial = fourth.measurement_comp_basis(state)
simulators = _simulators_sv(qc)
for simulator in simulators:
result = simulator.run_statistics(state)
final_states = result.get_final_states()
result_cbits = result.get_cbits()
for i, final_state in enumerate(final_states):
_, probs_final = fourth.measurement_comp_basis(final_state)
np.testing.assert_allclose(probs_initial, probs_final)
assert sum(result_cbits[i]) == 1
def test_runstatistics_teleportation(self):
"""
Test circuit run_statistics on teleportation circuit
"""
teleportation = _teleportation_circuit()
final_measurement = Measurement("start", targets=[2])
initial_measurement = Measurement("start", targets=[0])
original_state = tensor(rand_ket(2), basis(2, 0), basis(2, 0))
_, initial_probabilities = initial_measurement.measurement_comp_basis(original_state)
teleportation_results = teleportation.run_statistics(original_state)
states = teleportation_results.get_final_states()
probabilities = teleportation_results.get_probabilities()
for i, state in enumerate(states):
state_final = state
prob = probabilities[i]
_, final_probabilities = final_measurement.measurement_comp_basis(state_final)
np.testing.assert_allclose(initial_probabilities,
final_probabilities)
assert prob == pytest.approx(0.25, abs=1e-7)
mixed_state = sum(p * ket2dm(s) for p, s in zip(probabilities, states))
dm_state = ket2dm(original_state)
teleportation2 = _teleportation_circuit2()
final_state = teleportation2.run(dm_state)
_, probs1 = final_measurement.measurement_comp_basis(final_state)
_, probs2 = final_measurement.measurement_comp_basis(mixed_state)
np.testing.assert_allclose(probs1, probs2)
def test_run_teleportation(self):
"""
Test circuit run and mid-circuit measurement functionality
by repeating the teleportation circuit on multiple random kets
"""
teleportation = _teleportation_circuit()
state = tensor(rand_ket(2), basis(2, 0), basis(2, 0))
initial_measurement = Measurement("start", targets=[0])
_, initial_probabilities = initial_measurement.measurement_comp_basis(state)
state_final, probability = teleportation.run(state)
final_measurement = Measurement("start", targets=[2])
_, final_probabilities = final_measurement.measurement_comp_basis(state_final)
np.testing.assert_allclose(initial_probabilities, final_probabilities)
def test_qasm_teleportation():
filename = "teleportation.qasm"
filepath = Path(__file__).parent / 'qasm_files' / filename
teleportation = read_qasm(filepath)
final_measurement = Measurement("start", targets=[2])
initial_measurement = Measurement("start", targets=[0])
state = tensor(rand_ket(2), basis(2, 0), basis(2, 0))
_, initial_probabilities = initial_measurement.measurement_comp_basis(state)
states, probabilites = teleportation.run_statistics(state)
for i, state in enumerate(states):
final = state
prob = probabilites[i]
_, final_probabilities = final_measurement.measurement_comp_basis(final)
np.testing.assert_allclose(initial_probabilities,
final_probabilities)
assert prob == pytest.approx(0.25, abs=1e-7)
def test_runstatistics_teleportation(self):
"""
Test circuit run_statistics on teleportation circuit
"""
teleportation = _teleportation_circuit()
final_measurement = Measurement("start", targets=[2])
initial_measurement = Measurement("start", targets=[0])
state = tensor(rand_ket(2), basis(2, 0), basis(2, 0))
_, initial_probabilities = initial_measurement.measurement_comp_basis(state)
states, probabilites = teleportation.run_statistics(state)
for i, state in enumerate(states):
state_final = state
prob = probabilites[i]
_, final_probabilities = final_measurement.measurement_comp_basis(state_final)
np.testing.assert_allclose(initial_probabilities,
final_probabilities)
assert prob == pytest.approx(0.25, abs=1e-7)
def test_qasm_teleportation():
filename = "teleportation.qasm"
filepath = Path(__file__).parent / 'qasm_files' / filename
with pytest.warns(UserWarning, match="not preserved in QubitCircuit"):
teleportation = read_qasm(filepath)
final_measurement = Measurement("start", targets=[2])
initial_measurement = Measurement("start", targets=[0])
state = tensor(rand_ket(2), basis(2, 0), basis(2, 0))
_, initial_probabilities = initial_measurement.measurement_comp_basis(state)
teleportation_results = teleportation.run_statistics(state)
states = teleportation_results.get_final_states()
probabilities = teleportation_results.get_probabilities()
for i, state in enumerate(states):
final = state
prob = probabilities[i]
_, final_probabilities = final_measurement.measurement_comp_basis(final)
np.testing.assert_allclose(initial_probabilities,
final_probabilities)
assert prob == pytest.approx(0.25, abs=1e-7)
def test_measurement_comp_basis():
"""
Test measurements to test probability calculation in
computational basis measurments on a 3 qubit state
"""
qubit_kets = [rand_ket(2), rand_ket(2), rand_ket(2)]
qubit_dms = [ket2dm(qubit_kets[i]) for i in range(3)]
state = tensor(qubit_kets)
density_mat = tensor(qubit_dms)
for i in range(3):
m_i = Measurement("M" + str(i), i)
final_states, probabilities_state = m_i.measurement_comp_basis(state)
final_dms, probabilities_dm = m_i.measurement_comp_basis(density_mat)
amps = qubit_kets[i].full()
probabilities_i = [np.abs(amps[0][0])**2, np.abs(amps[1][0])**2]
np.testing.assert_allclose(probabilities_state, probabilities_dm)
np.testing.assert_allclose(probabilities_state, probabilities_i)
for j, final_state in enumerate(final_states):
np.testing.assert_allclose(final_dms[j], ket2dm(final_state))