Qiskit Backend

menos.qiskit.MENOSBackend, a Qiskit BackendV2.

from menos.qiskit import MENOSBackend

Class

class MENOSBackend(BackendV2)
MENOSBackend(provider=None, **fields)

**fields override the default options: MENOSBackend(shots=2048, seed_simulator=7) sets new defaults for every call. A field that is not a valid option raises AttributeError.

Properties

Property	Value
name	"menos"
description	"MENOS dense-engine simulator". A fixed label; the backend uses every engine, not only dense
backend_version	The installed menos package version
max_circuits	1
num_qubits	None: no fixed size; memory is the limit
target	A Target advertising exactly the supported gates plus measure and unitary
provider	None (there is no provider class)
options	See below

Options

Option	Default	Meaning
shots	1024	Number of samples
seed_simulator	None	Sampling seed; None draws a fresh one
want_statevector	False	Also return the exact statevector
noise_model	None	A qiskit_aer.noise.NoiseModel, simulated exactly by default. See Noise Models
noise_method	"exact"	"exact": a noisy circuit runs on the exact density matrix. "auto": the planner may also sample it with trajectories when that is cheaper or the only plan that fits. Any other value raises ValueError
time_budget_seconds	None	Wall-clock seconds one execution attempt may take. None: no budget. A run that overruns is replanned; with no plan left, run raises ResourceExceededError. Abandoned attempts appear in result.results[0].metadata["menos_replans"]. Must be finite and > 0, otherwise InvalidCircuitError. See Time Budgets
backend	None	None: the planner chooses CPU or CUDA. "cpu" or "cuda" forces one (see Forcing a backend). "cuda" raises UnsupportedFeatureError when CUDA cannot be used, and never falls back to the CPU. Any other value raises ValueError

backend.set_options(shots=…) changes defaults after construction.

run

MENOSBackend.run(run_input, **options) -> MENOSJob

Parameter	Meaning
run_input	One QuantumCircuit (a one-element list is also accepted)
**options	Overrides for shots, seed_simulator, want_statevector, noise_model, noise_method, time_budget_seconds, backend for this call

Raises	When
TypeError	run_input is not a QuantumCircuit, or noise_model is not an Aer NoiseModel
ValueError	run_input is a list of more than one circuit, noise_method is not "exact" or "auto", or backend is not None, "cpu" or "cuda"
AttributeError	An option name is not valid
InvalidCircuitError	Unbound parameters, nothing to produce, shots > 0 with no measurement, malformed circuit, a time_budget_seconds that is not finite and > 0
UnsupportedFeatureError	A gate or feature MENOS cannot represent, or backend="cuda" when this build has no CUDA support, no device is usable, or the circuit is noisy
ResourceExceededError	No plan fits the memory budget, or the time budget (at plan time, or after an overrun with no plan left)

The call is synchronous and returns a finished MENOSJob.

Verification

import inspect

from menos.qiskit import MENOSBackend

assert str(inspect.signature(MENOSBackend.__init__)) == "(self, provider=None, **fields) -> 'None'"
assert str(inspect.signature(MENOSBackend.run)) == "(self, run_input, **options) -> 'MENOSJob'"

backend = MENOSBackend(shots=64, seed_simulator=5)
assert dict(backend.options.items()) == {
    "shots": 64,
    "seed_simulator": 5,
    "want_statevector": False,
    "noise_model": None,
    "noise_method": "exact",
    "time_budget_seconds": None,
    "backend": None,
}
assert backend.name == "menos"
assert backend.max_circuits == 1
assert backend.num_qubits is None
assert backend.provider is None
assert backend.description == "MENOS dense-engine simulator"

Related

MENOSBackend guide · Running Jobs · Qiskit Integration