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)