def test_partial_exchange(self):
qubit_1 = 0
qubit_2 = 1
qasm_1 = QasmUtils.qasm_header(2)
qasm_1 += 'x q[{}];\n'.format(qubit_1)
qasm_2 = QasmUtils.qasm_header(2)
qasm_2 += 'x q[{}];\n'.format(qubit_2)
angles = [0, numpy.pi / 4, numpy.pi / 3, numpy.pi / 2, numpy.pi]
for angle in angles:
statevector_1 = QiskitSimBackend.\
statevector_from_qasm(qasm_1 + QasmUtils.partial_exchange(angle, qubit_1, qubit_2)).round(3)
expected_statevector_1 = numpy.array(
[0, numpy.cos(angle), -numpy.sin(angle), 0])
expected_statevector_1 = expected_statevector_1.round(3)
for i in range(len(statevector_1)):
self.assertEqual(statevector_1[i], expected_statevector_1[i])
statevector_2 = QiskitSimBackend.\
statevector_from_qasm(qasm_2 + QasmUtils.partial_exchange(angle, qubit_1, qubit_2)).round(3)
expected_statevector_2 = numpy.array(
[0, numpy.sin(angle), numpy.cos(angle), 0])
expected_statevector_2 = expected_statevector_2.round(3)
for i in range(len(statevector_2)):
self.assertEqual(statevector_2[i], expected_statevector_2[i])
def get_qasm(self, var_parameters):
assert len(var_parameters) == 1
qasm = QasmUtils.partial_exchange(-var_parameters[0],
self.qubits[0][0], self.qubits[1][0])
if {*self.qubits[0], *self.qubits[1]} != {*self.complement_qubits[0], *self.complement_qubits[1]} and \
{*self.qubits[0], *self.qubits[1]} != {*self.complement_qubits[1], *self.complement_qubits[0]}:
qasm += QasmUtils.partial_exchange(-self.sign * var_parameters[0],
self.complement_qubits[0][0],
self.complement_qubits[1][0])
return qasm
def get_qasm(self, var_parameters):
assert len(var_parameters) == self.n_var_parameters
var_parameters_cycle = itertools.cycle(var_parameters)
qasm = ['']
for block in range(self.n_blocks):
unoccupied_orbitals = list(range(self.n_electrons,
self.n_orbitals))
for occupied_orbital in reversed(range(0, self.n_electrons)):
if len(unoccupied_orbitals) == 0:
break
if occupied_orbital == self.n_electrons - 1:
virtual_orbital = self.n_electrons + block
else:
virtual_orbital = min(unoccupied_orbitals)
unoccupied_orbitals.remove(virtual_orbital)
# add a phase rotation for the excited orbitals only
angle = var_parameters_cycle.__next__()
qasm.append('rz({}) q[{}];\n'.format(angle, virtual_orbital))
angle = var_parameters_cycle.__next__()
qasm.append(
QasmUtils.partial_exchange(angle, occupied_orbital,
virtual_orbital))
# TODO add exchanges between the last unoccupied orbitals?
return ''.join(qasm)
def double_exchange_old(angle, qubit_pair_1, qubit_pair_2):
assert len(qubit_pair_1) == 2
assert len(qubit_pair_2) == 2
qasm = ['']
qasm.append(
QasmUtils.partial_exchange(angle, qubit_pair_1[1],
qubit_pair_2[0]))
qasm.append(
QasmUtils.partial_exchange(-angle, qubit_pair_1[0],
qubit_pair_2[1]))
qasm.append('cz q[{}], q[{}];\n'.format(qubit_pair_2[0],
qubit_pair_2[1]))
qasm.append(
QasmUtils.partial_exchange(-angle, qubit_pair_1[1],
qubit_pair_2[0]))
qasm.append(
QasmUtils.partial_exchange(angle, qubit_pair_1[0],
qubit_pair_2[1]))
# corrections
qasm.append('cz q[{}], q[{}];\n'.format(qubit_pair_2[0],
qubit_pair_2[1]))
return ''.join(qasm)
def get_qasm(self, var_parameters):
var_parameters_cycle = itertools.cycle(var_parameters)
count = 0
qasm = ['']
# add single qubit n rotations
# for qubit in range(self.n_orbitals):
# qasm.append('rz ({}) q[{}];\n'.format(var_parameters_cycle.__next__(), qubit))
# count += 1
# double orbital exchanges
for qubit in range(self.n_orbitals):
if qubit % 4 == 0:
q_0 = qubit
q_1 = (qubit + 1) % self.n_orbitals
q_2 = (qubit + 2) % self.n_orbitals
q_3 = (qubit + 3) % self.n_orbitals
q_4 = (qubit + 4) % self.n_orbitals
# qasm.append(DoubleExchangeAnsatzElement.double_exchange(var_parameters_cycle.__next__(), [q_0, q_1], [q_2, q_3]))
# count += 1
qasm.append(
DoubleExchangeAnsatzElement.double_exchange(
var_parameters_cycle.__next__(), [q_1, q_2],
[q_3, q_4]))
count += 1
# single orbital exchanges
for qubit in range(self.n_orbitals):
if qubit % 2 == 0:
qasm.append(
QasmUtils.partial_exchange(var_parameters_cycle.__next__(),
qubit,
(qubit + 1) % self.n_orbitals))
count += 1
qasm.append(
QasmUtils.partial_exchange(var_parameters_cycle.__next__(),
(qubit + 1) % self.n_orbitals,
(qubit + 2) % self.n_orbitals))
count += 1
assert count == len(var_parameters)
return ''.join(qasm)
def get_qasm(self, var_parameters):
assert len(var_parameters) == 1
return QasmUtils.partial_exchange(
-var_parameters[0], self.qubits[0][0], self.qubits[1][0]
) # the minus sign is important for consistence with the d_q_exc, as well obtaining the correct sign for grads...