def _permute_circuit(
circuit: QuantumCircuit,
measurement_qubits: Optional[Sequence[int]] = None,
preparation_qubits: Optional[Sequence[int]] = None,
):
"""Permute circuit qubits.
This permutes the circuit so that the specified preparation and measurement
qubits correspond to input and output qubits [0, ..., N-1] respectively
for the returned circuit.
"""
if measurement_qubits is None and preparation_qubits is None:
return circuit
total_qubits = circuit.num_qubits
total_clbits = circuit.num_clbits
if total_clbits:
perm_circ = QuantumCircuit(total_qubits, total_clbits)
else:
perm_circ = QuantumCircuit(total_qubits)
# Apply permutation to put prep qubits as [0, ..., M-1]
if preparation_qubits:
prep_qargs = list(preparation_qubits)
if len(preparation_qubits) != total_qubits:
prep_qargs += [
i for i in range(total_qubits)
if i not in preparation_qubits
]
perm_circ.append(
Permutation(total_qubits, prep_qargs).inverse(),
range(total_qubits))
# Apply original circuit
if total_clbits:
perm_circ = perm_circ.compose(circuit, range(total_qubits),
range(total_clbits))
else:
perm_circ = perm_circ.compose(circuit, range(total_qubits))
# Apply permutation to put meas qubits as [0, ..., M-1]
if measurement_qubits:
meas_qargs = list(measurement_qubits)
if len(measurement_qubits) != total_qubits:
meas_qargs += [
i for i in range(total_qubits)
if i not in measurement_qubits
]
perm_circ.append(Permutation(total_qubits, meas_qargs),
range(total_qubits))
return perm_circ
def _permute_circuit(self) -> QuantumCircuit:
"""Permute circuit qubits.
This permutes the circuit so that the specified preparation and measurement
qubits correspond to input and output qubits [0, ..., N-1] and [0, ..., M-1]
respectively for the returned circuit.
"""
default_range = tuple(range(self.num_qubits))
permute_meas = self._meas_qubits and self._meas_qubits != default_range
permute_prep = self._prep_qubits and self._prep_qubits != default_range
if not permute_meas and not permute_prep:
return self._circuit
total_qubits = self._circuit.num_qubits
total_clbits = self._circuit.num_clbits
if total_clbits:
perm_circ = QuantumCircuit(total_qubits, total_clbits)
else:
perm_circ = QuantumCircuit(total_qubits)
# Apply permutation to put prep qubits as [0, ..., M-1]
if self._prep_qubits:
prep_qargs = list(self._prep_qubits)
if len(self._prep_qubits) != total_qubits:
prep_qargs += [
i for i in range(total_qubits)
if i not in self._prep_qubits
]
perm_circ.append(
Permutation(total_qubits, prep_qargs).inverse(),
range(total_qubits))
# Apply original circuit
if total_clbits:
perm_circ = perm_circ.compose(self._circuit, range(total_qubits),
range(total_clbits))
else:
perm_circ = perm_circ.compose(self._circuit, range(total_qubits))
# Apply permutation to put meas qubits as [0, ..., M-1]
if self._meas_qubits:
meas_qargs = list(self._meas_qubits)
if len(self._meas_qubits) != total_qubits:
meas_qargs += [
i for i in range(total_qubits)
if i not in self._meas_qubits
]
perm_circ.append(Permutation(total_qubits, meas_qargs),
range(total_qubits))
return perm_circ
def test_permutation(self):
"""Test permutation circuit."""
circuit = Permutation(n_qubits=4, pattern=[1, 0, 3, 2])
expected = QuantumCircuit(4)
expected.swap(0, 1)
expected.swap(2, 3)
self.assertEqual(circuit, expected)
def build_QFT_0_to_k(nWires, k, measure=False):
r""" Builds the QFT on nWires wires up to the `k^{th}` state generates.
Note that the whole QFT can be generated in Qiskit using the `QFT` method
:param int nWires: number of wires
:param int k: number of gates in the output
:returns: QuantumCirctuit -- `k^{th}` first gates of the QFT circuit
"""
partial_QFT = QuantumCircuit(nWires)
gate_count = 0
if gate_count == k:
return partial_QFT
for wire in range(nWires):
partial_QFT.h(wire)
gate_count += 1
if gate_count == k:
return partial_QFT
for inlayer_nb in range(2, nWires - (wire - 1)):
partial_QFT.cu1(np.pi / (2**inlayer_nb), wire,
inlayer_nb + (wire - 1))
gate_count += 1
if gate_count == k:
return partial_QFT
partial_QFT.barrier()
SWAP = Permutation(nWires, [nWires - 1 - wire for wire in range(nWires)])
meas = QuantumCircuit(nWires, nWires)
meas.barrier(range(nWires))
meas.measure(range(nWires), range(nWires))
result = partial_QFT + SWAP + meas if measure else partial_QFT + SWAP
return result
def run(self, dag: DAGCircuit) -> DAGCircuit:
"""Run the LinearFunctionsToPermutations pass on `dag`.
Args:
dag: input dag.
Returns:
Output dag with LinearFunctions synthesized.
"""
for node in dag.named_nodes("linear_function"):
try:
pattern = node.op.permutation_pattern()
except CircuitError:
continue
permutation = Permutation(len(pattern), pattern)
dag.substitute_node(node, permutation.to_instruction())
return dag
def test_permutation(self):
"""Test permutation circuit."""
circuit = Permutation(num_qubits=4, pattern=[1, 0, 3, 2])
expected = QuantumCircuit(4)
expected.swap(0, 1)
expected.swap(2, 3)
expected = Operator(expected)
simulated = Operator(circuit)
self.assertTrue(expected.equiv(simulated))
def test_permutation(self):
"""Test permutation circuit.
TODO add a test using assertBooleanFunctionIsCorrect
"""
circuit = Permutation(num_qubits=4, pattern=[1, 0, 3, 2])
expected = QuantumCircuit(4)
expected.swap(0, 1)
expected.swap(2, 3)
self.assertEqual(circuit, expected)