def test_identity(self):
n_qubits = 5
transmed_i = reverse_jordan_wigner(self.identity, n_qubits)
expected_i = FermionOperator(())
self.assertTrue(transmed_i.isclose(expected_i))
retransmed_i = jordan_wigner(transmed_i)
self.assertTrue(self.identity.isclose(retransmed_i))
def test_zero(self):
n_qubits = 5
transmed_i = reverse_jordan_wigner(QubitOperator(), n_qubits)
expected_i = FermionOperator()
self.assertTrue(transmed_i.isclose(expected_i))
retransmed_i = jordan_wigner(transmed_i)
self.assertTrue(expected_i.isclose(retransmed_i))
def test_jordan_wigner_interaction_op_with_zero_term(self):
test_op = FermionOperator('1^ 2^ 3 4')
test_op += hermitian_conjugated(test_op)
interaction_op = get_interaction_operator(test_op)
interaction_op.constant = 0.0
retransformed_test_op = reverse_jordan_wigner(
jordan_wigner(interaction_op))
def test_get_interaction_operator_identity(self):
interaction_operator = InteractionOperator(-2j, self.one_body,
self.two_body)
qubit_operator = jordan_wigner(interaction_operator)
self.assertTrue(qubit_operator.isclose(-2j * QubitOperator(())))
self.assertEqual(
interaction_operator,
get_interaction_operator(reverse_jordan_wigner(qubit_operator),
self.n_qubits))
def test_jordan_wigner_twobody_interaction_op_allunique(self):
test_op = FermionOperator('1^ 2^ 3 4')
test_op += hermitian_conjugated(test_op)
retransformed_test_op = reverse_jordan_wigner(
jordan_wigner(get_interaction_operator(test_op)))
self.assertTrue(
normal_ordered(retransformed_test_op).isclose(
normal_ordered(test_op)))
def test_z(self):
pauli_z = QubitOperator(((2, 'Z'), ))
transmed_z = reverse_jordan_wigner(pauli_z)
expected = (FermionOperator(()) + FermionOperator(
((2, 1), (2, 0)), -2.))
self.assertTrue(transmed_z.isclose(expected))
retransmed_z = jordan_wigner(transmed_z)
self.assertTrue(pauli_z.isclose(retransmed_z))
def test_xy(self):
xy = QubitOperator(((4, 'X'), (5, 'Y')), -2.j)
transmed_xy = reverse_jordan_wigner(xy)
retransmed_xy = jordan_wigner(transmed_xy)
expected1 = -2j * (FermionOperator(((4, 1), ), 1j) - FermionOperator(
((4, 0), ), 1j))
expected2 = (FermionOperator(((5, 1), )) - FermionOperator(((5, 0), )))
expected = expected1 * expected2
self.assertTrue(xy.isclose(retransmed_xy))
self.assertTrue(
normal_ordered(transmed_xy).isclose(normal_ordered(expected)))
def test_yy(self):
yy = QubitOperator(((2, 'Y'), (3, 'Y')), 2.)
transmed_yy = reverse_jordan_wigner(yy)
retransmed_yy = jordan_wigner(transmed_yy)
expected1 = -(FermionOperator(((2, 1), ), 2.) + FermionOperator(
((2, 0), ), 2.))
expected2 = (FermionOperator(((3, 1), )) - FermionOperator(((3, 0), )))
expected = expected1 * expected2
self.assertTrue(yy.isclose(retransmed_yy))
self.assertTrue(
normal_ordered(transmed_yy).isclose(normal_ordered(expected)))
def test_xx(self):
xx = QubitOperator(((3, 'X'), (4, 'X')), 2.)
transmed_xx = reverse_jordan_wigner(xx)
retransmed_xx = jordan_wigner(transmed_xx)
expected1 = (FermionOperator(((3, 1), ), 2.) - FermionOperator(
((3, 0), ), 2.))
expected2 = (FermionOperator(((4, 1), ), 1.) + FermionOperator(
((4, 0), ), 1.))
expected = expected1 * expected2
self.assertTrue(xx.isclose(retransmed_xx))
self.assertTrue(
normal_ordered(transmed_xx).isclose(normal_ordered(expected)))
def test_yx(self):
yx = QubitOperator(((0, 'Y'), (1, 'X')), -0.5)
transmed_yx = reverse_jordan_wigner(yx)
retransmed_yx = jordan_wigner(transmed_yx)
expected1 = 1j * (FermionOperator(((0, 1), )) + FermionOperator(
((0, 0), )))
expected2 = -0.5 * (FermionOperator(((1, 1), )) + FermionOperator(
((1, 0), )))
expected = expected1 * expected2
self.assertTrue(yx.isclose(retransmed_yx))
self.assertTrue(
normal_ordered(transmed_yx).isclose(normal_ordered(expected)))
def get_qubit_expectations(self, qubit_operator):
"""Return expectations of QubitOperator in new QubitOperator.
Args:
qubit_operator: QubitOperator instance to be evaluated on
this InteractionRDM.
Returns:
QubitOperator: QubitOperator with coefficients
corresponding to expectation values of those operators.
Raises:
InteractionRDMError: Observable not contained in 1-RDM or 2-RDM.
"""
from fermilib.transforms import reverse_jordan_wigner
qubit_operator_expectations = copy.deepcopy(qubit_operator)
del qubit_operator_expectations.terms[()]
for qubit_term in qubit_operator_expectations.terms:
expectation = 0.
# Map qubits back to fermions.
reversed_fermion_operators = reverse_jordan_wigner(
QubitOperator(qubit_term), self.n_qubits)
reversed_fermion_operators = normal_ordered(
reversed_fermion_operators)
# Loop through fermion terms.
for fermion_term in reversed_fermion_operators.terms:
coefficient = reversed_fermion_operators.terms[fermion_term]
# Handle molecular term.
if FermionOperator(fermion_term).is_molecular_term():
if not fermion_term:
expectation += coefficient
else:
indices = [operator[0] for operator in fermion_term]
rdm_element = self[indices]
expectation += rdm_element * coefficient
# Handle non-molecular terms.
elif len(fermion_term) > 4:
raise InteractionRDMError('Observable not contained '
'in 1-RDM or 2-RDM.')
qubit_operator_expectations.terms[qubit_term] = expectation
return qubit_operator_expectations
def test_reverse_jordan_wigner(self):
transmed_operator = reverse_jordan_wigner(self.qubit_operator)
retransmed_operator = jordan_wigner(transmed_operator)
self.assertTrue(self.qubit_operator.isclose(retransmed_operator))
def test_y(self):
pauli_y = QubitOperator(((2, 'Y'), ))
transmed_y = reverse_jordan_wigner(pauli_y)
retransmed_y = jordan_wigner(transmed_y)
self.assertTrue(pauli_y.isclose(retransmed_y))
def test_bad_type(self):
with self.assertRaises(TypeError):
reverse_jordan_wigner(3)
def test_reverse_jw_linearity(self):
term1 = QubitOperator(((0, 'X'), (1, 'Y')), -0.5)
term2 = QubitOperator(((0, 'Y'), (1, 'X'), (2, 'Y'), (3, 'Y')), -1j)
op12 = reverse_jordan_wigner(term1) - reverse_jordan_wigner(term2)
self.assertTrue(op12.isclose(reverse_jordan_wigner(term1 - term2)))
def test_term(self):
transmed_term = reverse_jordan_wigner(self.term)
retransmed_term = jordan_wigner(transmed_term)
self.assertTrue(self.term.isclose(retransmed_term))
def test_yzxz(self):
yzxz = QubitOperator(((0, 'Y'), (1, 'Z'), (2, 'X'), (3, 'Z')))
transmed_yzxz = reverse_jordan_wigner(yzxz)
retransmed_yzxz = jordan_wigner(transmed_yzxz)
self.assertTrue(yzxz.isclose(retransmed_yzxz))
def test_identity_jwterm(self):
self.assertTrue(
FermionOperator(
()).isclose(reverse_jordan_wigner(QubitOperator(()))))
def test_x(self):
pauli_x = QubitOperator(((2, 'X'), ))
transmed_x = reverse_jordan_wigner(pauli_x)
retransmed_x = jordan_wigner(transmed_x)
self.assertTrue(pauli_x.isclose(retransmed_x))
def test_reverse_jw_too_few_n_qubits(self):
with self.assertRaises(ValueError):
reverse_jordan_wigner(self.operator_a, 0)
