def test_is_unitary():
"""Tests that common qubit gates are unitary."""
for gate in (igate(), hgate(), xgate(), ygate(), zgate(), cnot()):
assert is_unitary(gate)
for exp in np.linspace(start=0, stop=2 * np.pi, num=100):
assert is_unitary(cphase(exp))
def test_qubit_pi1_projector():
"""Tests correctness for |0><0| on a qubit."""
pi1 = computational_basis_projector(state=1)
correct_tensor = np.array([[0., 0.], [0., 1.]])
assert np.array_equal(pi1.tensor, correct_tensor)
assert is_projector(pi1)
assert not is_unitary(pi1)
assert pi1.__str__() == "|1><1|"
def test_qutrit_projectors():
"""Tests correctness for projectors on qutrits."""
dim = 3
for state in (0, 1, 2):
projector = computational_basis_projector(state, dim)
correct_tensor = np.zeros((dim, dim))
correct_tensor[state, state] = 1.
assert np.array_equal(projector.tensor, correct_tensor)
assert is_projector(projector)
assert not is_unitary(projector)
assert projector.__str__() == f"|{state}><{state}|"
def test_haar_random_unitary():
"""Tests single-qubit and two-qubit Haar random unitaries."""
for n in [2, 3, 4]:
for d in [2, 3, 5]:
gate = haar_random_unitary(nqudits=n, qudit_dimension=d, seed=1)
assert is_unitary(gate)