1"""qiskit_aer implementation of QiskitBackend"""
 2from typing import Literal
 3
 4from qiskit.providers import BackendV1, BackendV2
 5from qiskit.primitives import BackendSamplerV2, BackendEstimatorV2
 6from qiskit_ibm_runtime import Options
 7from qiskit_algorithms.optimizers import COBYLA
 8from qiskit_aer import AerSimulator
 9from qiskit_aer.noise import NoiseModel
10
11from quantum_launcher.routines.qiskit_routines.backends.qiskit_backend import QiskitBackend
12
13

[docs]
14class AerBackend(QiskitBackend):
15    """
16    QiskitBackend utilizing the qiskit_aer library. Runs local simulations only, utilizing CUDA capable gpus if available.
17    """
18
19    def __init__(
20        self,
21        name: Literal['local_simulator', 'backendv1v2'],
22        options: Options | None = None,
23        backendv1v2: BackendV1 | BackendV2 | None = None,
24        auto_transpile_level: Literal[0, 1, 2, 3] | None = None,
25        simulation_method: str = 'automatic',
26        simulation_device: Literal['CPU', 'GPU'] = 'CPU',
27    ) -> None:
28        self.method = simulation_method
29        self.device = simulation_device
30        super().__init__(name, options, backendv1v2, auto_transpile_level)
31
32    def _set_primitives_on_backend_name(self):
33        if self.name == 'local_simulator':
34            self.simulator = AerSimulator(method=self.method, device=self.device)
35        elif self.name == 'backendv1v2':
36            if self.backendv1v2 is None:
37                raise AttributeError(
38                    'Please indicate a backend when in backendv1v2 mode.')
39            noise_model = NoiseModel.from_backend(self.backendv1v2)
40            self.simulator = AerSimulator(method=self.method, device=self.device, noise_model=noise_model)
41        else:
42            raise ValueError(
43                f"Unsupported mode for this backend:'{self.name}'. Please use one of the following: ['local_simulator', 'backendv1v2']")
44
45        self.sampler = BackendSamplerV2(backend=self.simulator)
46        self.estimator = BackendEstimatorV2(backend=self.simulator)
47        self.optimizer = COBYLA()
48
49        self._configure_auto_behavior()
50

[docs]
51    def set_options(self, **fields):
52        """Set additional options for the instance AerSimulator"""
53        self.simulator.set_options(**fields)