Add AerSimulator backend

README.md

@@ -48,20 +48,20 @@ $ python
 ```python
 import qiskit
 from qiskit import IBMQ
-from qiskit.providers.aer import QasmSimulator
+from qiskit.providers.aer import AerSimulator
 
 # Generate 3-qubit GHZ state
-circ = qiskit.QuantumCircuit(3, 3)
+circ = qiskit.QuantumCircuit(3)
 circ.h(0)
 circ.cx(0, 1)
 circ.cx(1, 2)
-circ.measure([0, 1, 2], [0, 1 ,2])
+circ.measure_all()
 
 # Construct an ideal simulator
-sim = QasmSimulator()
+aersim = AerSimulator()
 
 # Perform an ideal simulation
-result_ideal = qiskit.execute(circ, sim).result()
+result_ideal = qiskit.execute(circ, aersim).result()
 counts_ideal = result_ideal.get_counts(0)
 print('Counts(ideal):', counts_ideal)
 # Counts(ideal): {'000': 493, '111': 531}
@@ -70,11 +70,11 @@ print('Counts(ideal):', counts_ideal)
 # This simulator backend will be automatically configured
 # using the device configuration and noise model 
 provider = IBMQ.load_account()
-vigo_backend = provider.get_backend('ibmq_vigo')
-vigo_sim = QasmSimulator.from_backend(vigo_backend)
+backend = provider.get_backend('ibmq_athens')
+aersim_backend = AerSimulator.from_backend(backend)
 
 # Perform noisy simulation
-result_noise = qiskit.execute(circ, vigo_sim).result()
+result_noise = qiskit.execute(circ, aersim_backend).result()
 counts_noise = result_noise.get_counts(0)
 
 print('Counts(noise):', counts_noise)

qiskit/providers/aer/__init__.py

@@ -28,13 +28,21 @@
 Simulator Backends
 ==================
 
+.. autosummary::
+    :toctree: ../stubs/
+
+    AerSimulator
+    PulseSimulator
+
+Legacy Simulator Backends
+=========================
+
 .. autosummary::
     :toctree: ../stubs/
 
     QasmSimulator
     StatevectorSimulator
     UnitarySimulator
-    PulseSimulator
 
 Job Class
 =========

qiskit/providers/aer/aerprovider.py

@@ -16,6 +16,7 @@
 from qiskit.providers import ProviderV1 as Provider
 from qiskit.providers.providerutils import filter_backends
 
+from .backends.aer_simulator import AerSimulator
 from .backends.qasm_simulator import QasmSimulator
 from .backends.statevector_simulator import StatevectorSimulator
 from .backends.unitary_simulator import UnitarySimulator
@@ -25,14 +26,37 @@
 class AerProvider(Provider):
     """Provider for Qiskit Aer backends."""
 
+    _BACKENDS = None
+
     def __init__(self):
-        # Populate the list of Aer simulator backends.
-        self._backends = [
-            ('qasm_simulator', QasmSimulator),
-            ('statevector_simulator', StatevectorSimulator),
-            ('unitary_simulator', UnitarySimulator),
-            ('pulse_simulator', PulseSimulator)
-        ]
+        if AerProvider._BACKENDS is None:
+            # Populate the list of Aer simulator backends.
+            methods = AerSimulator().available_methods()
+            devices = AerSimulator().available_devices()
+            backends = []
+            for method in methods:
+                name = 'aer_simulator'
+                if method not in [None, 'automatic']:
+                    name += f'_{method}'
+                device_name = 'CPU'
+                backends.append((name, AerSimulator, method, device_name))
+
+                # Add GPU device backends
+                if method in ['statevector', 'density_matrix', 'unitary']:
+                    for device in devices:
+                        if device != 'CPU':
+                            new_name = f'{name}_{device}'.lower()
+                            device_name = device
+                            backends.append((new_name, AerSimulator, method, device_name))
+
+            # Add legacy backend names
+            backends += [
+                ('qasm_simulator', QasmSimulator, None, None),
+                ('statevector_simulator', StatevectorSimulator, None, None),
+                ('unitary_simulator', UnitarySimulator, None, None),
+                ('pulse_simulator', PulseSimulator, None, None)
+            ]
+            AerProvider._BACKENDS = backends
 
     def get_backend(self, name=None, **kwargs):
         return super().get_backend(name=name, **kwargs)
@@ -42,9 +66,14 @@ def backends(self, name=None, filters=None, **kwargs):
         # Instantiate a new backend instance so if config options
         # are set they will only last as long as that backend object exists
         backends = []
-        for backend_name, backend_cls in self._backends:
+        for backend_name, backend_cls, method, device in self._BACKENDS:
+            opts = {'provider': self}
+            if method is not None:
+                opts['method'] = method
+            if device is not None:
+                opts['device'] = device
             if name is None or backend_name == name:
-                backends.append(backend_cls(provider=self))
+                backends.append(backend_cls(**opts))
         return filter_backends(backends, filters=filters)
 
     def __str__(self):

qiskit/providers/aer/backends/__init__.py

@@ -14,6 +14,7 @@
 Aer Provider Simulator Backends
 """
 
+from .aer_simulator import AerSimulator
 from .qasm_simulator import QasmSimulator
 from .statevector_simulator import StatevectorSimulator
 from .unitary_simulator import UnitarySimulator