def required_predicates(self) -> List[Predicate]:
preds = [
NoSymbolsPredicate(),
GateSetPredicate(_GATE_SET),
]
if not self._MACHINE_DEBUG:
assert self.device is not None
preds.append(MaxNQubitsPredicate(len(self.device.nodes)))
return preds
def required_predicates(self) -> List[Predicate]:
preds = [
NoClassicalControlPredicate(),
NoFastFeedforwardPredicate(),
NoMidMeasurePredicate(),
NoSymbolsPredicate(),
GateSetPredicate(ionq_gates),
MaxNQubitsPredicate(self._max_n_qubits),
]
return preds
def required_predicates(self) -> List[Predicate]:
preds = [
NoClassicalControlPredicate(),
NoFastFeedforwardPredicate(),
NoMidMeasurePredicate(),
NoSymbolsPredicate(),
GateSetPredicate({
OpType.Rx, OpType.Ry, OpType.XXPhase, OpType.Measure,
OpType.Barrier
}),
]
if self._max_n_qubits is not None:
preds.append(MaxNQubitsPredicate(self._max_n_qubits))
return preds
def __init__(
self,
local: bool = False,
s3_bucket: str = "",
s3_folder: str = "",
device_type: str = "quantum-simulator",
provider: str = "amazon",
device: str = "sv1",
):
"""
Construct a new braket backend.
If `local=True`, other parameters are ignored.
:param local: use simulator running on local machine
:param s3_bucket: name of S3 bucket to store results
:param s3_folder: name of folder ("key") in S3 bucket to store results in
:param device_type: device type from device ARN (e.g. "qpu")
:param provider: provider name from device ARN (e.g. "ionq", "rigetti", ...)
:paran device: device name from device ARN (e.g. "ionQdevice", "Aspen-8", ...)
"""
super().__init__()
if local:
self._device = LocalSimulator()
self._device_type = _DeviceType.LOCAL
else:
self._device = AwsDevice(
"arn:aws:braket:::" +
"/".join(["device", device_type, provider, device]))
self._s3_dest = (s3_bucket, s3_folder)
aws_device_type = self._device.type
if aws_device_type == AwsDeviceType.SIMULATOR:
self._device_type = _DeviceType.SIMULATOR
elif aws_device_type == AwsDeviceType.QPU:
self._device_type = _DeviceType.QPU
else:
raise ValueError(f"Unsupported device type {aws_device_type}")
props = self._device.properties.dict()
paradigm = props["paradigm"]
n_qubits = paradigm["qubitCount"]
connectivity_graph = None # None means "fully connected"
if self._device_type == _DeviceType.QPU:
connectivity = paradigm["connectivity"]
if connectivity["fullyConnected"]:
self._all_qubits: List = list(range(n_qubits))
else:
connectivity_graph = connectivity["connectivityGraph"]
# Convert strings to ints
connectivity_graph = dict(
(int(k), [int(v) for v in l])
for k, l in connectivity_graph.items())
self._all_qubits = sorted(connectivity_graph.keys())
if n_qubits < len(self._all_qubits):
# This can happen, at least on rigetti devices, and causes errors.
# As a kludgy workaround, remove some qubits from the architecture.
self._all_qubits = self._all_qubits[:(
n_qubits - len(self._all_qubits))]
connectivity_graph = dict(
(k, [v for v in l if v in self._all_qubits])
for k, l in connectivity_graph.items()
if k in self._all_qubits)
self._characteristics: Optional[Dict] = props["provider"]
else:
self._all_qubits = list(range(n_qubits))
self._characteristics = None
device_info = props["action"][DeviceActionType.JAQCD]
supported_ops = set(op.lower()
for op in device_info["supportedOperations"])
supported_result_types = device_info["supportedResultTypes"]
self._result_types = set()
for rt in supported_result_types:
rtname = rt["name"]
rtminshots = rt["minShots"]
rtmaxshots = rt["maxShots"]
self._result_types.add(rtname)
if rtname == "StateVector":
self._supports_state = True
# Always use n_shots = 0 for StateVector
elif rtname == "Amplitude":
pass # Always use n_shots = 0 for Amplitude
elif rtname == "Probability":
self._probability_min_shots = rtminshots
self._probability_max_shots = rtmaxshots
elif rtname == "Expectation":
self._supports_expectation = True
self._expectation_allows_nonhermitian = False
self._expectation_min_shots = rtminshots
self._expectation_max_shots = rtmaxshots
elif rtname == "Sample":
self._supports_shots = True
self._supports_counts = True
self._sample_min_shots = rtminshots
self._sample_max_shots = rtmaxshots
elif rtname == "Variance":
self._variance_min_shots = rtminshots
self._variance_max_shots = rtmaxshots
self._multiqs = set()
self._singleqs = set()
if not {"cnot", "rx", "rz"} <= supported_ops:
# This is so that we can define RebaseCustom without prior knowledge of the
# gate set. We could do better than this, by having a few different options
# for the CX- and tk1-replacement circuits. But it seems all existing
# backends support these gates.
raise NotImplementedError(
"Device must support cnot, rx and rz gates.")
for t in supported_ops:
tkt = _gate_types[t]
if tkt is not None:
if t in _multiq_gate_types:
if self._device_type == _DeviceType.QPU and t in [
"ccnot", "cswap"
]:
# FullMappingPass can't handle 3-qubit gates, so ignore them.
continue
self._multiqs.add(tkt)
else:
self._singleqs.add(tkt)
self._req_preds = [
NoClassicalControlPredicate(),
NoFastFeedforwardPredicate(),
NoMidMeasurePredicate(),
NoSymbolsPredicate(),
GateSetPredicate(self._multiqs | self._singleqs),
MaxNQubitsPredicate(n_qubits),
]
if connectivity_graph is None:
arch = FullyConnected(n_qubits)
else:
arch = Architecture([(k, v) for k, l in connectivity_graph.items()
for v in l])
if self._device_type == _DeviceType.QPU:
assert self._characteristics is not None
node_errs = {}
edge_errs = {}
schema = self._characteristics["braketSchemaHeader"]
if schema == IONQ_SCHEMA:
fid = self._characteristics["fidelity"]
mean_1q_err = 1 - fid["1Q"]["mean"]
mean_2q_err = 1 - fid["2Q"]["mean"]
err_1q_cont = QubitErrorContainer(self._singleqs)
for optype in self._singleqs:
err_1q_cont.add_error((optype, mean_1q_err))
err_2q_cont = QubitErrorContainer(self._multiqs)
for optype in self._multiqs:
err_2q_cont.add_error((optype, mean_2q_err))
for node in arch.nodes:
node_errs[node] = err_1q_cont
for coupling in arch.coupling:
edge_errs[coupling] = err_2q_cont
elif schema == RIGETTI_SCHEMA:
specs = self._characteristics["specs"]
specs1q, specs2q = specs["1Q"], specs["2Q"]
for node in arch.nodes:
nodespecs = specs1q[f"{node.index[0]}"]
err_1q_cont = QubitErrorContainer(self._singleqs)
for optype in self._singleqs:
err_1q_cont.add_error(
(optype, 1 - nodespecs.get("f1QRB", 1)))
err_1q_cont.add_readout(nodespecs.get("fRO", 1))
node_errs[node] = err_1q_cont
for coupling in arch.coupling:
node0, node1 = coupling
n0, n1 = node0.index[0], node1.index[0]
couplingspecs = specs2q[f"{min(n0,n1)}-{max(n0,n1)}"]
err_2q_cont = QubitErrorContainer({OpType.CZ})
err_2q_cont.add_error(
(OpType.CZ, 1 - couplingspecs.get("fCZ", 1)))
edge_errs[coupling] = err_2q_cont
self._tket_device = Device(node_errs, edge_errs, arch)
if connectivity_graph is not None:
self._req_preds.append(ConnectivityPredicate(
self._tket_device))
else:
self._tket_device = None
self._rebase_pass = RebaseCustom(
self._multiqs,
Circuit(),
self._singleqs,
lambda a, b, c: Circuit(1).Rz(c, 0).Rx(b, 0).Rz(a, 0),
)
self._squash_pass = SquashCustom(
self._singleqs,
lambda a, b, c: Circuit(1).Rz(c, 0).Rx(b, 0).Rz(a, 0),
)