def test_invalid_qubit_state_vector_size(self):
"""Test that an exception is raised if the state
vector is the wrong size"""
dev = DefaultQubitTF(wires=2)
state = np.array([0, 1])
with pytest.raises(ValueError,
match=r"State vector must be of length 2\*\*wires"):
dev.apply([qml.QubitStateVector(state, wires=[0, 1])])
def test_invalid_basis_state(self, tol):
"""Test that an exception is raised if the basis state is invalid"""
dev = DefaultQubitTF(wires=4)
state = np.array([0, 0, 1, 2])
with pytest.raises(
ValueError,
match=r"BasisState parameter must consist of 0 or 1 integers"):
dev.apply([qml.BasisState(state, wires=[0, 1, 2, 3])])
def test_invalid_qubit_state_vector_norm(self):
"""Test that an exception is raised if the state
vector is not normalized"""
dev = DefaultQubitTF(wires=2)
state = np.array([0, 12])
with pytest.raises(
ValueError,
match=r"Sum of amplitudes-squared does not equal one"):
dev.apply([qml.QubitStateVector(state, wires=[0])])
def test_invalid_basis_state_length(self, tol):
"""Test that an exception is raised if the basis state is the wrong size"""
dev = DefaultQubitTF(wires=4)
state = np.array([0, 0, 1, 0])
with pytest.raises(
ValueError,
match=r"BasisState parameter and wires must be of equal length"
):
dev.apply([qml.BasisState(state, wires=[0, 1, 2])])
def test_qubit_state_vector(self, init_state, tol):
"""Test qubit state vector application"""
dev = DefaultQubitTF(wires=1)
state = init_state(1)
dev.apply([qml.QubitStateVector(state, wires=[0])])
res = dev.state
expected = state
assert isinstance(res, tf.Tensor)
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_two_qubit_parameters(self, init_state, op, func, theta, tol):
"""Test two qubit parametrized operations"""
dev = DefaultQubitTF(wires=2)
state = init_state(2)
queue = [qml.QubitStateVector(state, wires=[0, 1])]
queue += [op(theta, wires=[0, 1])]
dev.apply(queue)
res = dev.state
expected = func(theta) @ state
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_three_qubit_no_parameters(self, init_state, op, mat, tol):
"""Test non-parametrized three qubit operations"""
dev = DefaultQubitTF(wires=3)
state = init_state(3)
queue = [qml.QubitStateVector(state, wires=[0, 1, 2])]
queue += [op(wires=[0, 1, 2])]
dev.apply(queue)
res = dev.state
expected = mat @ state
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_invalid_state_prep(self):
"""Test that an exception is raised if a state preparation is not the
first operation in the circuit."""
dev = DefaultQubitTF(wires=2)
state = np.array([0, 12])
with pytest.raises(
qml.DeviceError,
match=
r"cannot be used after other Operations have already been applied",
):
dev.apply([qml.PauliZ(0), qml.QubitStateVector(state, wires=[0])])
def test_qubit_unitary(self, init_state, mat, tol):
"""Test application of arbitrary qubit unitaries"""
N = int(np.log2(len(mat)))
dev = DefaultQubitTF(wires=N)
state = init_state(N)
queue = [qml.QubitStateVector(state, wires=range(N))]
queue += [qml.QubitUnitary(mat, wires=range(N))]
dev.apply(queue)
res = dev.state
expected = mat @ state
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_single_qubit_no_parameters(self, init_state, op, mat, tol):
"""Test non-parametrized single qubit operations"""
dev = DefaultQubitTF(wires=1)
state = init_state(1)
queue = [qml.QubitStateVector(state, wires=[0])]
queue += [op(wires=0)]
dev.apply(queue)
res = dev.state
expected = mat @ state
assert isinstance(res, tf.Tensor)
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_basis_state(self, tol):
"""Test basis state initialization"""
dev = DefaultQubitTF(wires=4)
state = np.array([0, 0, 1, 0])
dev.apply([qml.BasisState(state, wires=[0, 1, 2, 3])])
res = dev.state
expected = np.zeros([2**4])
expected[np.ravel_multi_index(state, [2] * 4)] = 1
assert isinstance(res, tf.Tensor)
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_controlled_rotation(self, init_state, tol):
"""Test three axis controlled-rotation gate"""
dev = DefaultQubitTF(wires=2)
state = init_state(2)
a = 0.542
b = 1.3432
c = -0.654
queue = [qml.QubitStateVector(state, wires=[0, 1])]
queue += [qml.CRot(a, b, c, wires=[0, 1])]
dev.apply(queue)
res = dev.state
expected = CRot3(a, b, c) @ state
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_inverse_operation(self, init_state, tol):
"""Test that the inverse of an operation is correctly applied"""
"""Test three axis rotation gate"""
dev = DefaultQubitTF(wires=1)
state = init_state(1)
a = 0.542
b = 1.3432
c = -0.654
queue = [qml.QubitStateVector(state, wires=[0])]
queue += [qml.Rot(a, b, c, wires=0).inv()]
dev.apply(queue)
res = dev.state
expected = np.linalg.inv(Rot3(a, b, c)) @ state
assert np.allclose(res, expected, atol=tol, rtol=0)