def get_excitation_list_qasm(excitation_list, var_parameters, gate_counter):
qasm = ['']
# iterate over all excitations (each excitation is represented by a sum of products of pauli operators)
for i, excitation in enumerate(excitation_list):
# print('Excitation ', i) # testing
# iterate over the terms of each excitation (each term is a product of pauli operators, on different qubits)
# TODO replace with the function from QasmUtils
for exponent_term in excitation.terms:
exponent_angle = var_parameters[i] * excitation.terms[exponent_term]
assert exponent_angle.real == 0
exponent_angle = exponent_angle.imag
qasm.append(QasmUtils.exponent_qasm(exponent_term, exponent_angle))
return ''.join(qasm)
def test_exponent_statevector(self):
exp_operator = ((0, 'X'), (1, 'Z'), (2, 'Z'))
qasm = QasmUtils.qasm_header(3)
qasm += QasmUtils.exponent_qasm(exp_operator, -numpy.pi / 2)
statevector = QiskitSimBackend.statevector_from_qasm(qasm)
expected_statevector = numpy.zeros(8)
expected_statevector[1] = 1
self.assertEqual(len(expected_statevector), len(statevector))
for i in range(len(statevector)):
self.assertEqual(statevector[i].round(3),
expected_statevector[i].round(3))
def test_exponent_statevectors(self):
qubit_operators = []
# only symetric qubit operators will works, because qiskit and openfermion use different qubit orderings
qubit_operators.append(openfermion.QubitOperator('Z0 Y1 Z2'))
qubit_operators.append(openfermion.QubitOperator('X0 Y1 X2'))
qubit_operators.append(openfermion.QubitOperator('Y0 X1 X2 Y3'))
for qubit_operator in qubit_operators:
qubit_operator_tuple = list(qubit_operator.terms.keys())[0]
n_qubits = len(qubit_operator_tuple)
for angle in range(10):
angle = 2 * numpy.pi / 10
# <<< create a statevector using QiskitSimulation.get_exponent_qasm >>>
qasm = QasmUtils.qasm_header(n_qubits)
qasm += QasmUtils.exponent_qasm(qubit_operator_tuple, angle)
qiskit_statevector = QiskitSimBackend.statevector_from_qasm(
qasm)
qiskit_statevector = qiskit_statevector * numpy.exp(
1j * angle) # correct for a global phase
qiskit_statevector = qiskit_statevector.round(
2) # round for the purpose of testing
# <<< create a statevector using MatrixCalculation.get_qubit_operator_exponent_matrix >>>
exp_matrix = MatrixUtils.get_excitation_matrix(
1j * qubit_operator, n_qubits, angle).todense()
# prepare initial statevector corresponding to state |0>
array_statevector = numpy.zeros(2**n_qubits)
array_statevector[0] = 1
# update statevector
array_statevector = numpy.array(
exp_matrix.dot(array_statevector))[0].round(
2) # round for the purpose of testing
# <<<< compare both state vectors >>>>
self.assertEqual(len(array_statevector),
len(qiskit_statevector))
# check the components of the two vectors are equal
for i in range(len(qiskit_statevector)):
self.assertEqual(qiskit_statevector[i],
array_statevector[i])