def complete_acquaintance_strategy(
qubit_order: Sequence['cirq.Qid'],
acquaintance_size: int = 0,
swap_gate: 'cirq.Gate' = ops.SWAP) -> 'cirq.Circuit':
"""Returns an acquaintance strategy with can handle the given number of qubits.
Args:
qubit_order: The qubits on which the strategy should be defined.
acquaintance_size: The maximum number of qubits to be acted on by
an operation.
swap_gate: The gate used to swap logical indices.
Returns:
A circuit capable of implementing any set of k-local operations.
Raises:
ValueError: If `acquaintance_size` is negative.
"""
if acquaintance_size < 0:
raise ValueError('acquaintance_size must be non-negative.')
if acquaintance_size == 0:
return circuits.Circuit()
if acquaintance_size > len(qubit_order):
return circuits.Circuit()
if acquaintance_size == len(qubit_order):
return circuits.Circuit(acquaint(*qubit_order))
strategy = circuits.Circuit((acquaint(q) for q in qubit_order))
for size_to_acquaint in range(2, acquaintance_size + 1):
expose_acquaintance_gates(strategy)
replace_acquaintance_with_swap_network(strategy, qubit_order,
size_to_acquaint, swap_gate)
return strategy
def _two_qubit_clifford_matrices(q_0: 'cirq.Qid', q_1: 'cirq.Qid',
cliffords: Cliffords) -> np.ndarray:
mats = []
# Total number of different gates in the two-qubit Clifford group.
clifford_group_size = 11520
starters = []
for idx_0 in range(24):
subset = []
for idx_1 in range(24):
circuit = circuits.Circuit(
_two_qubit_clifford_starters(q_0, q_1, idx_0, idx_1, cliffords))
subset.append(protocols.unitary(circuit))
starters.append(subset)
mixers = []
# Add the identity for the case where there is no mixer.
mixers.append(np.eye(4))
for idx_2 in range(1, 20):
circuit = circuits.Circuit(
_two_qubit_clifford_mixers(q_0, q_1, idx_2, cliffords))
mixers.append(protocols.unitary(circuit))
for i in range(clifford_group_size):
idx_0, idx_1, idx_2 = _split_two_q_clifford_idx(i)
mats.append(np.matmul(mixers[idx_2], starters[idx_0][idx_1]))
return np.array(mats)
def test_depolarizer_different_gate():
q1 = ops.QubitId()
q2 = ops.QubitId()
cnot = Job(circuits.Circuit([
circuits.Moment([ops.CNOT(q1, q2)]),
]))
allerrors = DepolarizerChannel(
probability=1.0,
depolarizing_gates=[xmon_gates.ExpZGate(),
xmon_gates.ExpWGate()])
p0 = Symbol(DepolarizerChannel._parameter_name + '0')
p1 = Symbol(DepolarizerChannel._parameter_name + '1')
p2 = Symbol(DepolarizerChannel._parameter_name + '2')
p3 = Symbol(DepolarizerChannel._parameter_name + '3')
error_sweep = (Points(p0.name, [1.0]) + Points(p1.name, [1.0]) +
Points(p2.name, [1.0]) + Points(p3.name, [1.0]))
cnot_then_z = Job(
circuits.Circuit([
circuits.Moment([ops.CNOT(q1, q2)]),
circuits.Moment([
xmon_gates.ExpZGate(half_turns=p0).on(q1),
xmon_gates.ExpZGate(half_turns=p1).on(q2)
]),
circuits.Moment([
xmon_gates.ExpWGate(half_turns=p2).on(q1),
xmon_gates.ExpWGate(half_turns=p3).on(q2)
])
]), cnot.sweep * error_sweep)
assert allerrors.transform_job(cnot) == cnot_then_z
def _strat_commutes_from_operation(
v1: Any,
v2: Any,
*,
atol: float,
) -> Union[bool, NotImplementedType, None]:
if not isinstance(v1, ops.Operation) or not isinstance(v2, ops.Operation):
return NotImplemented
if set(v1.qubits).isdisjoint(v2.qubits):
return True
from cirq import circuits
circuit12 = circuits.Circuit(v1, v2)
circuit21 = circuits.Circuit(v2, v1)
# Don't create gigantic matrices.
if np.product(qid_shape_protocol.qid_shape(circuit12)) > 2**10:
return NotImplemented # coverage: ignore
m12 = unitary_protocol.unitary(circuit12, default=None)
m21 = unitary_protocol.unitary(circuit21, default=None)
if m12 is None:
return NotImplemented
return np.allclose(m12, m21, atol=atol)
def _cleanup_operations(operations: Sequence[ops.Operation]):
circuit = circuits.Circuit(operations)
circuit = merge_single_qubit_gates_to_phased_x_and_z(circuit)
circuit = eject_phased_paulis(circuit)
circuit = eject_z(circuit)
circuit = circuits.Circuit(circuit.all_operations(), strategy=circuits.InsertStrategy.EARLIEST)
return list(circuit.all_operations())
def _commutes_(
self,
other: Any,
*,
atol: Union[int,
float] = 1e-8) -> Union[bool, NotImplementedType, None]:
"""Determine if this Operation commutes with the object"""
if not isinstance(other, Operation):
return NotImplemented
if hasattr(other, 'qubits') and set(self.qubits).isdisjoint(
other.qubits):
return True
from cirq import circuits
circuit12 = circuits.Circuit(self, other)
circuit21 = circuits.Circuit(other, self)
# Don't create gigantic matrices.
shape = protocols.qid_shape_protocol.qid_shape(circuit12)
if np.product(shape) > 2**10:
return NotImplemented # coverage: ignore
m12 = protocols.unitary_protocol.unitary(circuit12, default=None)
m21 = protocols.unitary_protocol.unitary(circuit21, default=None)
if m12 is None or m21 is None:
return NotImplemented
return np.allclose(m12, m21, atol=atol)
def complete_acquaintance_strategy(qubit_order: Sequence[ops.Qid],
acquaintance_size: int=0,
) -> circuits.Circuit:
"""
Returns an acquaintance strategy capable of executing a gate corresponding
to any set of at most acquaintance_size qubits.
Args:
qubit_order: The qubits on which the strategy should be defined.
acquaintance_size: The maximum number of qubits to be acted on by
an operation.
Returns:
An circuit capable of implementing any set of k-local
operation.
"""
if acquaintance_size < 0:
raise ValueError('acquaintance_size must be non-negative.')
elif acquaintance_size == 0:
return circuits.Circuit(device=UnconstrainedAcquaintanceDevice)
if acquaintance_size > len(qubit_order):
return circuits.Circuit(device=UnconstrainedAcquaintanceDevice)
if acquaintance_size == len(qubit_order):
return circuits.Circuit.from_ops(
acquaint(*qubit_order), device=UnconstrainedAcquaintanceDevice)
strategy = circuits.Circuit.from_ops(
(acquaint(q) for q in qubit_order),
device=UnconstrainedAcquaintanceDevice)
for size_to_acquaint in range(2, acquaintance_size + 1):
expose_acquaintance_gates(strategy)
replace_acquaintance_with_swap_network(
strategy, qubit_order, size_to_acquaint)
return strategy
def _split_into_unitary_then_general(
circuit: 'cirq.Circuit',
) -> Tuple['cirq.Circuit', 'cirq.Circuit']:
"""Splits the circuit into a unitary prefix and non-unitary suffix.
The splitting happens in a per-qubit fashion. A non-unitary operation on
qubit A will cause later operations on A to be part of the non-unitary
suffix, but later operations on other qubits will continue to be put into
the unitary part (as long as those qubits have had no non-unitary operation
up to that point).
"""
blocked_qubits: Set[cirq.Qid] = set()
unitary_prefix = circuits.Circuit()
general_suffix = circuits.Circuit()
for moment in circuit:
unitary_part = []
general_part = []
for op in moment:
qs = set(op.qubits)
if not protocols.has_unitary(op) or not qs.isdisjoint(blocked_qubits):
blocked_qubits |= qs
if qs.isdisjoint(blocked_qubits):
unitary_part.append(op)
else:
general_part.append(op)
if unitary_part:
unitary_prefix.append(ops.Moment(unitary_part))
if general_part:
general_suffix.append(ops.Moment(general_part))
return unitary_prefix, general_suffix
def _cleanup_operations(operations: List[ops.Operation]):
circuit = circuits.Circuit(operations)
optimizers.merge_single_qubit_gates.merge_single_qubit_gates_into_phased_x_z(circuit)
optimizers.eject_phased_paulis.EjectPhasedPaulis().optimize_circuit(circuit)
optimizers.eject_z.EjectZ().optimize_circuit(circuit)
circuit = circuits.Circuit(circuit.all_operations(), strategy=circuits.InsertStrategy.EARLIEST)
return list(circuit.all_operations())
def split_into_matching_protocol_then_general(
circuit: 'cirq.Circuit',
predicate: Callable[['cirq.Operation'], bool],
) -> Tuple['cirq.Circuit', 'cirq.Circuit']:
"""Splits the circuit into a matching prefix and non-matching suffix.
The splitting happens in a per-qubit fashion. A non-matching operation on
qubit A will cause later operations on A to be part of the non-matching
suffix, but later operations on other qubits will continue to be put into
the matching part (as long as those qubits have had no non-matching operation
up to that point).
"""
blocked_qubits: Set[cirq.Qid] = set()
matching_prefix = circuits.Circuit()
general_suffix = circuits.Circuit()
for moment in circuit:
matching_part = []
general_part = []
for op in moment:
qs = set(op.qubits)
if not predicate(op) or not qs.isdisjoint(blocked_qubits):
blocked_qubits |= qs
if qs.isdisjoint(blocked_qubits):
matching_part.append(op)
else:
general_part.append(op)
if matching_part:
matching_prefix.append(ops.Moment(matching_part))
if general_part:
general_suffix.append(ops.Moment(general_part))
return matching_prefix, general_suffix
def swap_rzz(theta: float, q0: ops.Qid, q1: ops.Qid) -> ops.OP_TREE:
"""
An implementation of SWAP * EXP(1j theta ZZ) using three sycamore gates.
This builds off of the zztheta method. A sycamore gate following the
zz-gate is a SWAP EXP(1j (THETA - pi/24) ZZ).
Args:
theta: exp(1j * theta )
q0: First qubit id to operate on
q1: Second qubit id to operate on
Returns:
The circuit that implements ZZ followed by a swap
"""
# Set interaction part.
circuit = circuits.Circuit()
angle_offset = np.pi / 24 - np.pi / 4
circuit.append(google.SYC(q0, q1))
circuit.append(rzz(theta - angle_offset, q0, q1))
# Get the intended circuit.
intended_circuit = circuits.Circuit(
ops.SWAP(q0, q1),
ops.ZZPowGate(exponent=2 * theta / np.pi,
global_shift=-0.5).on(q0, q1))
yield create_corrected_circuit(intended_circuit, circuit, q0, q1)
def test_leaves_singleton():
m = MergeRotations(0.000001)
q = ops.QubitId()
c = circuits.Circuit([circuits.Moment([ops.X(q)])])
m.optimization_at(c, 0, c.operation_at(q, 0))
assert c == circuits.Circuit([circuits.Moment([ops.X(q)])])
def test_removes_identity_sequence():
q = ops.QubitId()
assert_optimizes(before=circuits.Circuit([
circuits.Moment([ops.Z(q)]),
circuits.Moment([ops.H(q)]),
circuits.Moment([ops.X(q)]),
circuits.Moment([ops.H(q)]),
]),
after=circuits.Circuit())
def test_leaves_big():
m = circuits.DropNegligible(0.001)
q = ops.QubitId()
c = circuits.Circuit([circuits.Moment([ops.Z(q)**0.1])])
assert m.optimization_at(c, 0, c.operation_at(q, 0)) is None
d = circuits.Circuit(c.moments)
m.optimize_circuit(d)
assert d == c
def test_clears_paired_cnot():
q0 = ops.QubitId()
q1 = ops.QubitId()
assert_optimizes(
before=circuits.Circuit([
circuits.Moment([ops.CNOT(q0, q1)]),
circuits.Moment([ops.CNOT(q0, q1)]),
]),
after=circuits.Circuit())
def mapped_circuit(self, deep: bool = False) -> 'cirq.Circuit':
"""Applies all maps to the contained circuit and returns the result.
Args:
deep: If true, this will also call mapped_circuit on any
CircuitOperations this object contains.
Returns:
The contained circuit with all other member variables (repetitions,
qubit mapping, parameterization, etc.) applied to it. This behaves
like `cirq.decompose(self)`, but preserving moment structure.
"""
circuit = self.circuit.unfreeze()
circuit = circuit.transform_qubits(lambda q: self.qubit_map.get(q, q))
if self.repetitions < 0:
circuit = circuit**-1
has_measurements = protocols.is_measurement(circuit)
if has_measurements:
circuit = protocols.with_measurement_key_mapping(
circuit, self.measurement_key_map)
circuit = protocols.resolve_parameters(circuit,
self.param_resolver,
recursive=False)
if deep:
def map_deep(op: 'cirq.Operation') -> 'cirq.OP_TREE':
return op.mapped_circuit(
deep=True) if isinstance(op, CircuitOperation) else op
if self.repetition_ids is None:
return circuit.map_operations(map_deep)
if not has_measurements:
return circuit.map_operations(map_deep) * abs(self.repetitions)
# Path must be constructed from the top down.
rekeyed_circuit = circuits.Circuit(
protocols.with_key_path(circuit, self.parent_path + (rep, ))
for rep in self.repetition_ids)
return rekeyed_circuit.map_operations(map_deep)
if self.repetition_ids is None:
return circuit
if not has_measurements:
return circuit * abs(self.repetitions)
def rekey_op(op: 'cirq.Operation', rep: str):
"""Update measurement keys in `op` to include repetition ID `rep`."""
rekeyed_op = protocols.with_key_path(op,
self.parent_path + (rep, ))
if rekeyed_op is NotImplemented:
return op
return rekeyed_op
return circuits.Circuit(
circuit.map_operations(lambda op: rekey_op(op, rep))
for rep in self.repetition_ids)
def test_ignores_2qubit_target():
m = MergeRotations(0.000001)
q = ops.QubitId()
q2 = ops.QubitId()
c = circuits.Circuit([
circuits.Moment([ops.CZ(q, q2)]),
])
m.optimization_at(c, 0, c.operation_at(q, 0))
assert c == circuits.Circuit([circuits.Moment([ops.CZ(q, q2)])])
def _to_circuit(program: 'cirq.CIRCUIT_LIKE') -> 'cirq.Circuit':
result = None
if isinstance(program, circuits.Circuit):
# No change needed.
result = program
elif isinstance(program, ops.Gate):
result = circuits.Circuit(program.on(*devices.LineQid.for_gate(program)))
else:
# It should be an OP_TREE.
result = circuits.Circuit(program)
return cast('cirq.Circuit', result)
def test_clears_small():
m = circuits.DropNegligible(0.001)
q = ops.QubitId()
c = circuits.Circuit([circuits.Moment([ops.Z(q)**0.000001])])
assert (m.optimization_at(c, 0, c.operation_at(q, 0)) ==
circuits.PointOptimizationSummary(clear_span=1,
clear_qubits=[q],
new_operations=[]))
m.optimize_circuit(c)
assert c == circuits.Circuit([circuits.Moment()])
def test_drop():
q1 = ops.QubitId()
q2 = ops.QubitId()
assert_optimizes(before=circuits.Circuit([
circuits.Moment(),
circuits.Moment(),
circuits.Moment([ops.CNOT(q1, q2)]),
circuits.Moment(),
]),
after=circuits.Circuit([
circuits.Moment([ops.CNOT(q1, q2)]),
]))
def circuit(self) -> 'cirq.Circuit':
result = circuits.Circuit()
for col in self._sub_cell_cols_sealed():
body = circuits.Circuit(cell.operations() for cell in col
if cell is not None)
if body:
basis_change = circuits.Circuit(cell.basis_change()
for cell in col
if cell is not None)
result += basis_change
result += body
result += basis_change**-1
return result
def estimate_single_qubit_readout_errors(
sampler: 'cirq.Sampler',
*,
qubits: Iterable['cirq.Qid'],
repetitions: int = 1000) -> SingleQubitReadoutCalibrationResult:
"""Estimate single-qubit readout error.
For each qubit, prepare the |0⟩ state and measure. Calculate how often a 1
is measured. Also, prepare the |1⟩ state and calculate how often a 0 is
measured. The state preparations and measurements are done in parallel,
i.e., for the first experiment, we actually prepare every qubit in the |0⟩
state and measure them simultaneously.
Args:
sampler: The quantum engine or simulator to run the circuits.
qubits: The qubits being tested.
repetitions: The number of measurement repetitions to perform.
Returns:
A SingleQubitReadoutCalibrationResult storing the readout error
probabilities as well as the number of repetitions used to estimate
the probabilities. Also stores a timestamp indicating the time when
data was finished being collected from the sampler.
"""
qubits = list(qubits)
zeros_circuit = circuits.Circuit(ops.measure_each(*qubits, key_func=repr))
ones_circuit = circuits.Circuit(ops.X.on_each(*qubits),
ops.measure_each(*qubits, key_func=repr))
zeros_result = sampler.run(zeros_circuit, repetitions=repetitions)
ones_result = sampler.run(ones_circuit, repetitions=repetitions)
timestamp = time.time()
zero_state_errors = {
q: np.mean(zeros_result.measurements[repr(q)])
for q in qubits
}
one_state_errors = {
q: 1 - np.mean(ones_result.measurements[repr(q)])
for q in qubits
}
return SingleQubitReadoutCalibrationResult(
zero_state_errors=zero_state_errors,
one_state_errors=one_state_errors,
repetitions=repetitions,
timestamp=timestamp,
)
def test_ignores_czs_separated_by_outer_cz():
q00 = ops.QubitId()
q01 = ops.QubitId()
q10 = ops.QubitId()
assert_optimizes(
before=circuits.Circuit([
circuits.Moment([ops.CZ(q00, q01)]),
circuits.Moment([ops.CZ(q00, q10)]),
circuits.Moment([ops.CZ(q00, q01)]),
]),
after=circuits.Circuit([
circuits.Moment([ops.CZ(q00, q01)]),
circuits.Moment([ops.CZ(q00, q10)]),
circuits.Moment([ops.CZ(q00, q01)]),
]))
def single_qubit_state_tomography(
sampler: 'cirq.Sampler',
qubit: 'cirq.Qid',
circuit: 'cirq.AbstractCircuit',
repetitions: int = 1000,
) -> TomographyResult:
"""Single-qubit state tomography.
The density matrix of the output state of a circuit is measured by first
doing projective measurements in the z-basis, which determine the
diagonal elements of the matrix. A X/2 or Y/2 rotation is then added before
the z-basis measurement, which determines the imaginary and real parts of
the off-diagonal matrix elements, respectively.
See Vandersypen and Chuang, Rev. Mod. Phys. 76, 1037 for details.
Args:
sampler: The quantum engine or simulator to run the circuits.
qubit: The qubit under test.
circuit: The circuit to execute on the qubit before tomography.
repetitions: The number of measurements for each basis rotation.
Returns:
A TomographyResult object that stores and plots the density matrix.
"""
circuit_z = circuit + circuits.Circuit(ops.measure(qubit, key='z'))
results = sampler.run(circuit_z, repetitions=repetitions)
rho_11 = np.mean(results.measurements['z'])
rho_00 = 1.0 - rho_11
circuit_x = circuits.Circuit(circuit,
ops.X(qubit)**0.5, ops.measure(qubit,
key='z'))
results = sampler.run(circuit_x, repetitions=repetitions)
rho_01_im = np.mean(results.measurements['z']) - 0.5
circuit_y = circuits.Circuit(circuit,
ops.Y(qubit)**-0.5, ops.measure(qubit,
key='z'))
results = sampler.run(circuit_y, repetitions=repetitions)
rho_01_re = 0.5 - np.mean(results.measurements['z'])
rho_01 = rho_01_re + 1j * rho_01_im
rho_10 = np.conj(rho_01)
rho = np.array([[rho_00, rho_01], [rho_10, rho_11]])
return TomographyResult(rho)
def test_correct_mappings():
a, b, c = cirq.LineQubit.range(3)
cirq.testing.assert_equivalent_computational_basis_map(
maps={
0b01: 0b01,
0b10: 0b10
},
circuit=circuits.Circuit(cirq.IdentityGate(num_qubits=2).on(a, b)))
cirq.testing.assert_equivalent_computational_basis_map(
maps={
0b001: 0b100,
0b010: 0b010,
0b100: 0b001,
},
circuit=circuits.Circuit(cirq.SWAP(a, c), cirq.I(b)))
def __init__(self,
circuit: circuits.Circuit = circuits.Circuit(),
sweep: study.Sweep = study.UnitSweep,
repetitions: int = 1) -> None:
self.circuit = circuit
self.sweep = sweep
self.repetitions = repetitions
def rzz(theta: float, q0: ops.Qid, q1: ops.Qid) -> ops.OP_TREE:
"""Generate exp(-1j * theta * zz) from Sycamore gates.
Args:
theta: rotation parameter
q0: First qubit id to operate on
q1: Second qubit id to operate on
Returns:
a Cirq program implementing the Ising gate
rtype:
cirq.OP_Tree
"""
phi = -np.pi / 24
c_phi = np.cos(2 * phi)
target_unitary = scipy.linalg.expm(-1j * theta * UNITARY_ZZ)
if abs(np.cos(theta)) > c_phi:
c2 = abs(np.sin(theta)) / c_phi
else:
c2 = abs(np.cos(theta)) / c_phi
# Prepare program that has same Schmidt coeffs as exp(1j theta ZZ)
program = circuits.Circuit(google.SYC.on(q0, q1),
ops.rx(2 * np.arccos(c2)).on(q1),
google.SYC.on(q0, q1))
yield create_corrected_circuit(target_unitary, program, q0, q1)
def convert_circuit(self, circuit: circuits.Circuit) -> circuits.Circuit:
new_circuit = circuits.Circuit()
for moment in circuit:
for op in moment.operations:
new_circuit.append(self.convert_one(op))
return transformers.merge_single_qubit_gates_to_phased_x_and_z(
new_circuit)
def generate_boixo_2018_supremacy_circuits_v2(
qubits: Iterable[devices.GridQubit], cz_depth: int, seed: int
) -> circuits.Circuit:
"""Generates Google Random Circuits v2 as in github.com/sboixo/GRCS cz_v2.
See also https://arxiv.org/abs/1807.10749
Args:
qubits: qubit grid in which to generate the circuit.
cz_depth: number of layers with CZ gates.
seed: seed for the random instance.
Returns:
A circuit corresponding to instance
inst_{n_rows}x{n_cols}_{cz_depth+1}_{seed}
The mapping of qubits is cirq.GridQubit(j,k) -> q[j*n_cols+k]
(as in the QASM mapping)
"""
non_diagonal_gates = [ops.pauli_gates.X ** (1 / 2), ops.pauli_gates.Y ** (1 / 2)]
rand_gen = random.Random(seed).random
circuit = circuits.Circuit()
# Add an initial moment of Hadamards
circuit.append(ops.common_gates.H(qubit) for qubit in qubits)
layer_index = 0
if cz_depth:
layer_index = _add_cz_layer(layer_index, circuit)
# In the first moment, add T gates when possible
for qubit in qubits:
if not circuit.operation_at(qubit, 1):
circuit.append(ops.common_gates.T(qubit), strategy=InsertStrategy.EARLIEST)
for moment_index in range(2, cz_depth + 1):
layer_index = _add_cz_layer(layer_index, circuit)
# Add single qubit gates in the same moment
for qubit in qubits:
if not circuit.operation_at(qubit, moment_index):
last_op = circuit.operation_at(qubit, moment_index - 1)
if last_op:
gate = cast(ops.GateOperation, last_op).gate
# Add a random non diagonal gate after a CZ
if gate == ops.CZ:
circuit.append(
_choice(rand_gen, non_diagonal_gates).on(qubit),
strategy=InsertStrategy.EARLIEST,
)
# Add a T gate after a non diagonal gate
elif not gate == ops.T:
circuit.append(ops.common_gates.T(qubit), strategy=InsertStrategy.EARLIEST)
# Add a final moment of Hadamards
circuit.append(
[ops.common_gates.H(qubit) for qubit in qubits], strategy=InsertStrategy.NEW_THEN_INLINE
)
return circuit
def _fix_single_qubit_gates_around_kak_interaction(
*,
desired: 'cirq.KakDecomposition',
operations: List['cirq.Operation'],
qubits: Sequence['cirq.Qid'],
) -> Iterator['cirq.Operation']:
"""Adds single qubit operations to complete a desired interaction.
Args:
desired: The kak decomposition of the desired operation.
qubits: The pair of qubits that is being operated on.
operations: A list of operations that composes into the desired kak
interaction coefficients, but may not have the desired before/after
single qubit operations or the desired global phase.
Returns:
A list of operations whose kak decomposition approximately equals the
desired kak decomposition.
"""
actual = linalg.kak_decomposition(circuits.Circuit(operations))
def dag(a: np.ndarray) -> np.ndarray:
return np.transpose(np.conjugate(a))
for k in range(2):
g = ops.MatrixGate(
dag(actual.single_qubit_operations_before[k])
@ desired.single_qubit_operations_before[k])
yield g(qubits[k])
yield from operations
for k in range(2):
g = ops.MatrixGate(desired.single_qubit_operations_after[k] @ dag(
actual.single_qubit_operations_after[k]))
yield g(qubits[k])
yield ops.GlobalPhaseOperation(desired.global_phase / actual.global_phase)