def test_imul_qubit_op():
op1 = QubitOperator(((0, 'Y'), (3, 'X'), (8, 'Z'), (11, 'X')), 3.j)
op2 = QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 0.5)
op1 *= op2
correct_term = ((0, 'Y'), (1, 'X'), (3, 'Z'), (11, 'X'))
assert len(op1.terms) == 1
assert correct_term in op1.terms
def test_renormalize():
operator = QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 1)
operator += QubitOperator(((2, 'Z'), (3, 'Y')), 1)
operator.renormalize()
for term in operator.terms:
assert operator.terms[term] == pytest.approx(1 / numpy.sqrt(2.))
assert operator.induced_norm(2) == pytest.approx(1.)
def test_mul_multiple_terms():
operator = QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 0.5)
operator += QubitOperator(((1, 'Z'), (3, 'X'), (8, 'Z')), 1.2)
operator += QubitOperator(((1, 'Z'), (3, 'Y'), (9, 'Z')), 1.4j)
res = operator * operator
correct = QubitOperator((), 0.5**2 + 1.2**2 + 1.4j**2)
correct += QubitOperator(((1, 'Y'), (3, 'Z')), 2j * 1j * 0.5 * 1.2)
assert res == correct
def test_imul_qubit_op_2():
op3 = QubitOperator(((1, 'Y'), (0, 'X')), -1j)
op4 = QubitOperator(((1, 'Y'), (0, 'X'), (2, 'Z')), -1.5)
op3 *= op4
op4 *= op3
assert ((2, 'Z'), ) in op3.terms
assert op3.terms[((2, 'Z'), )] == 1.5j
assert op4.terms[((0, 'X'), (1, 'Y'))] == -2.25j
def test_get_operators():
"""Tests get_operators() with an operator with two terms."""
operator_00 = QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 1)
operator_01 = QubitOperator(((2, 'Z'), (3, 'Y')), 1)
sum_operator = operator_00 + operator_01
operators = list(sum_operator.get_operators())
assert operators in [[operator_00, operator_01],
[operator_01, operator_00]]
def test_mul_out_of_place():
op1 = QubitOperator(((0, 'Y'), (3, 'X'), (8, 'Z'), (11, 'X')), 3.j)
op2 = QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 0.5)
op3 = op1 * op2
correct_coefficient = 1.j * 3.0j * 0.5
correct_term = ((0, 'Y'), (1, 'X'), (3, 'Z'), (11, 'X'))
assert op1 == QubitOperator(((0, 'Y'), (3, 'X'), (8, 'Z'), (11, 'X')), 3.j)
assert op2 == QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 0.5)
assert op3 == QubitOperator(correct_term, correct_coefficient)
def test_imul_bidir():
op_a = QubitOperator(((1, 'Y'), (0, 'X')), -1j)
op_b = QubitOperator(((1, 'Y'), (0, 'X'), (2, 'Z')), -1.5)
op_a *= op_b
op_b *= op_a
assert ((2, 'Z'), ) in op_a.terms
assert op_a.terms[((2, 'Z'), )] == 1.5j
assert ((0, 'X'), (1, 'Y')) in op_b.terms
assert op_b.terms[((0, 'X'), (1, 'Y'))] == -2.25j
class TestTimeEvolutionOfHamiltonian:
@pytest.fixture(
params=[
PauliSum(
[
PauliTerm("X", 0) * PauliTerm("X", 1),
PauliTerm("Y", 0, 0.5) * PauliTerm("Y", 1),
PauliTerm("Z", 0, 0.3) * PauliTerm("Z", 1),
]
),
QubitOperator("[X0 X1] + 0.5[Y0 Y1] + 0.3[Z0 Z1]"),
]
)
def hamiltonian(self, request):
return request.param
@pytest.mark.parametrize("time", [0.1]) # [0.1, 0.4, 1.0])
@pytest.mark.parametrize("order", [2]) # [1, 2, 3])
def test_evolution_with_numerical_time_produces_correct_result(
self, hamiltonian, time, order
):
cirq_qubits = cirq.LineQubit(0), cirq.LineQubit(1)
expected_cirq_circuit = _cirq_exponentiate_hamiltonian(
hamiltonian, cirq_qubits, time, order
)
reference_unitary = cirq.unitary(expected_cirq_circuit)
unitary = time_evolution(hamiltonian, time, trotter_order=order).to_unitary()
assert compare_unitary(unitary, reference_unitary, tol=1e-10)
@pytest.mark.parametrize("time_value", [0.1, 0.4, 1.0])
@pytest.mark.parametrize("order", [1, 2, 3])
def test_time_evolution_with_symbolic_time_produces_correct_unitary(
self, hamiltonian, time_value, order
):
time_symbol = sympy.Symbol("t")
symbols_map = [(time_symbol, time_value)]
cirq_qubits = cirq.LineQubit(0), cirq.LineQubit(1)
expected_cirq_circuit = _cirq_exponentiate_hamiltonian(
hamiltonian, cirq_qubits, time_value, order
)
reference_unitary = cirq.unitary(expected_cirq_circuit)
unitary = (
time_evolution(hamiltonian, time_symbol, trotter_order=order)
.evaluate(symbols_map)
.to_unitary()
)
assert compare_unitary(unitary, reference_unitary, tol=1e-10)
class TestTimeEvolutionDerivatives:
@pytest.fixture(
params=[
PauliSum(
[
PauliTerm("X", 0) * PauliTerm("X", 1),
PauliTerm("Y", 0, 0.5) * PauliTerm("Y", 1),
PauliTerm("Z", 0, 0.3) * PauliTerm("Z", 1),
]
),
QubitOperator("[X0 X1] + 0.5[Y0 Y1] + 0.3[Z0 Z1]"),
]
)
def hamiltonian(self, request):
return request.param
@pytest.mark.parametrize("time", [0.4, sympy.Symbol("t")])
def test_time_evolution_derivatives_gives_correct_number_of_derivatives_and_factors(
self, time, hamiltonian
):
order = 3
reference_factors_1 = [1.0 / order, 0.5 / order, 0.3 / order] * 3
reference_factors_2 = [-1.0 * x for x in reference_factors_1]
derivatives, factors = time_evolution_derivatives(
hamiltonian, time, trotter_order=order
)
if isinstance(hamiltonian, QubitOperator):
terms = list(hamiltonian.get_operators())
elif isinstance(hamiltonian, PauliSum):
terms = hamiltonian.terms
assert len(derivatives) == order * 2 * len(terms)
assert len(factors) == order * 2 * len(terms)
assert factors[0:18:2] == reference_factors_1
assert factors[1:18:2] == reference_factors_2
def generate_operator(begin, end):
"""Returns a sum of Z operators at qubit [begin, end)."""
operator = QubitOperator.zero()
for i in range(begin, end):
operator += QubitOperator(((i, 'Z'), ), 1)
return operator
* trotter_order
)
@pytest.mark.parametrize(
"term, time, expected_unitary",
[
(PauliTerm("X", 0) * PauliTerm("X", 1), np.pi, -np.eye(4)),
(
PauliTerm("Y", 0, 0.5) * PauliTerm("Y", 1),
np.pi,
np.diag([1j, -1j, -1j, 1j])[::-1],
),
(PauliTerm("Z", 0) * PauliTerm("Z", 1), np.pi, -np.eye(4)),
(PauliTerm("I", 0) * PauliTerm("I", 1), np.pi, -np.eye(2)),
(QubitOperator("[X0 X1]"), np.pi, -np.eye(4)),
(
QubitOperator("0.5 [Y0 Y1]"),
np.pi,
np.diag([1j, -1j, -1j, 1j])[::-1],
),
(QubitOperator("[Z0 Z1]"), np.pi, -np.eye(4)),
],
)
class TestTimeEvolutionOfTerm:
def test_evolving_pauli_term_with_numerical_time_gives_correct_unitary(
self, term, time, expected_unitary
):
actual_unitary = time_evolution_for_term(term, time).to_unitary()
np.testing.assert_array_almost_equal(actual_unitary, expected_unitary)
def test_mul_npfloat64():
operator = QubitOperator(((1, 'X'), (3, 'Y')), 0.5)
res = operator * numpy.float64(0.5)
assert res == QubitOperator(((1, 'X'), (3, 'Y')), 0.5 * 0.5)
def test_mul_bad_multiplier():
operator = QubitOperator(((1, 'Y'), (0, 'X')), -1j)
with pytest.raises(TypeError):
operator = operator * "0.5"
def test_different_indices_commute():
qubit_op = QubitOperator('X1')
assert qubit_op.different_indices_commute is True
def test_imul_scalar(multiplier):
loc_op = ((1, 'X'), (2, 'Y'))
qubit_op = QubitOperator(loc_op)
qubit_op *= multiplier
assert qubit_op.terms[loc_op] == pytest.approx(multiplier)
def test_imul_inplace():
qubit_op = QubitOperator("X1")
prev_id = id(qubit_op)
qubit_op *= 3.
assert id(qubit_op) == prev_id
def test_init_simplify():
assert QubitOperator("X0 X0") == QubitOperator.identity()
assert QubitOperator("X1 X1") == QubitOperator.identity()
assert QubitOperator("Y0 Y0") == QubitOperator.identity()
assert QubitOperator("Z0 Z0") == QubitOperator.identity()
assert QubitOperator("X0 Y0") == QubitOperator("Z0", coefficient=1j)
assert QubitOperator("Y0 X0") == QubitOperator("Z0", coefficient=-1j)
assert QubitOperator("X0 Y0 Z0") == 1j * QubitOperator.identity()
assert QubitOperator("Y0 Z0 X0") == 1j * QubitOperator.identity()
assert QubitOperator("Z0 Y0 X0") == -1j * QubitOperator.identity()
assert QubitOperator("X1 Y0 X1") == QubitOperator("Y0")
assert QubitOperator("Y1 Y1 Y1") == QubitOperator("Y1")
assert QubitOperator("Y2 Y2 Y2 Y2") == QubitOperator.identity()
assert QubitOperator("Y3 Y3 Y3 Y3 Y3") == QubitOperator("Y3")
assert QubitOperator("Y4 Y4 Y4 Y4 Y4 Y4") == QubitOperator.identity()
assert QubitOperator("X0 Y1 Y0 X1") == QubitOperator("Z0 Z1")
assert QubitOperator("X0 Y1 Z3 X2 Z3 Y0") == QubitOperator("Z0 Y1 X2",
coefficient=1j)
def test_mul_by_scalarzero():
operator = QubitOperator(((1, 'Y'), (0, 'X')), -1j) * 0
assert ((0, 'X'), (1, 'Y')) in operator.terms
assert operator.terms[((0, 'X'), (1, 'Y'))] == pytest.approx(0.0)
def test_renormalize_error():
operator = QubitOperator()
with pytest.raises(ZeroDivisionError):
operator.renormalize()
def test_get_operators_one():
"""Tests get_operators() with an operator with a single term."""
operator = QubitOperator(((1, 'X'), (3, 'Y'), (8, 'Z')), 1)
operators = list(operator.get_operators())
assert operators == [operator]