Removal of deprecated Qiskit 2.0 related code

docs/tutorials/2_device_noise_simulation.ipynb

@@ -40,7 +40,7 @@
    "source": [
     "## Device Backend Noise Model\n",
     "\n",
-    "The *Qiskit Aer* device noise model automatically generates a simplified noise model for a real device. This model is generated using the calibration information reported in the `BackendProperties` of a device and takes into account\n",
+    "The *Qiskit Aer* device noise model automatically generates a simplified noise model for a real device. This model is generated using the calibration information reported in the properties of a device and takes into account\n",
     "\n",
     "* The *gate_error* probability of each basis gate on each qubit.\n",
     "* The *gate_length* of each basis gate on each qubit.\n",

qiskit_aer/backends/aer_compiler.py

@@ -27,7 +27,6 @@
 from qiskit.circuit.classical.types import Bool, Uint
 from qiskit.circuit.library import Initialize
 from qiskit.providers.options import Options
-from qiskit.pulse import Schedule, ScheduleBlock
 from qiskit.circuit import Store
 from qiskit.circuit.controlflow import (
     WhileLoopOp,
@@ -85,7 +84,7 @@ def compile(self, circuits, optypes=None):
                    compiled circuit optypes for each circuit if
                    optypes kwarg is not None.
         """
-        if isinstance(circuits, (QuantumCircuit, Schedule, ScheduleBlock)):
+        if isinstance(circuits, QuantumCircuit):
             circuits = [circuits]
         if optypes is None:
             compiled_optypes = len(circuits) * [None]

qiskit_aer/backends/aer_simulator.py

@@ -15,10 +15,8 @@
 
 import copy
 import logging
-from warnings import warn
-from qiskit.providers import convert_to_target
 from qiskit.providers.options import Options
-from qiskit.providers.backend import BackendV2, BackendV1
+from qiskit.providers.backend import BackendV2
 
 from ..version import __version__
 from .aerbackend import AerBackend, AerError
@@ -34,7 +32,6 @@
 
 # pylint: disable=import-error, no-name-in-module, abstract-method
 from .controller_wrappers import aer_controller_execute
-from .name_mapping import NAME_MAPPING
 
 logger = logging.getLogger(__name__)
 
@@ -858,28 +855,9 @@ def from_backend(cls, backend, **options):
             )
             properties = target_to_backend_properties(backend.target)
             target = backend.target
-        elif isinstance(backend, BackendV1):
-            # BackendV1 will be removed in Qiskit 2.0, so we will remove this soon
-            warn(
-                " from_backend using V1 based backend is deprecated as of Aer 0.15"
-                " and will be removed no sooner than 3 months from that release"
-                " date. Please use backends based on V2.",
-                DeprecationWarning,
-                stacklevel=2,
-            )
-            # Get configuration and properties from backend
-            configuration = backend.configuration()
-            properties = copy.copy(backend.properties())
-
-            # Customize configuration name
-            name = configuration.backend_name
-            configuration.backend_name = f"aer_simulator_from({name})"
-
-            target = convert_to_target(configuration, properties, None, NAME_MAPPING)
         else:
             raise TypeError(
-                "The backend argument requires a BackendV2 or BackendV1 object, "
-                f"not a {type(backend)} object"
+                "The backend argument requires a BackendV2 object, " f"not a {type(backend)} object"
             )
         # Use automatic noise model if none is provided
         if "noise_model" not in options:

qiskit_aer/backends/aerbackend.py

@@ -23,8 +23,6 @@
 
 from qiskit.circuit import QuantumCircuit, ParameterExpression, Delay
 from qiskit.providers import BackendV2 as Backend
-from qiskit.providers.models.backendstatus import BackendStatus
-from qiskit.pulse import Schedule, ScheduleBlock
 from qiskit.result import Result
 from qiskit.transpiler import CouplingMap
 from qiskit.transpiler.target import Target
@@ -181,7 +179,7 @@ def run(self, circuits, parameter_binds=None, **run_options):
         Raises:
             ValueError: if run is not implemented
         """
-        if isinstance(circuits, (QuantumCircuit, Schedule, ScheduleBlock)):
+        if isinstance(circuits, QuantumCircuit):
             circuits = [circuits]
 
         return self._run_circuits(circuits, parameter_binds, **run_options)
@@ -442,20 +440,6 @@ def clear_options(self):
         self._options_configuration = {}
         self._options_properties = {}
 
-    def status(self):
-        """Return backend status.
-
-        Returns:
-            BackendStatus: the status of the backend.
-        """
-        return BackendStatus(
-            backend_name=self.name,
-            backend_version=self.configuration().backend_version,
-            operational=True,
-            pending_jobs=0,
-            status_msg="",
-        )
-
     def _execute_circuits_job(
         self, circuits, parameter_binds, run_options, job_id="", format_result=True
     ):
@@ -536,7 +520,7 @@ def _format_results(output):
 
     def _compile(self, circuits, **run_options):
         """Compile circuits and noise model"""
-        if isinstance(circuits, (QuantumCircuit, Schedule, ScheduleBlock)):
+        if isinstance(circuits, QuantumCircuit):
             circuits = [circuits]
         optypes = [circuit_optypes(circ) for circ in circuits]
 
@@ -582,9 +566,7 @@ def _assemble_noise_model(self, circuits, optypes, **run_options):
 
         # Check if circuits contain quantum error instructions
         for idx, circ in enumerate(run_circuits):
-            if QuantumChannelInstruction in optypes[idx] and not isinstance(
-                circ, (Schedule, ScheduleBlock)
-            ):
+            if QuantumChannelInstruction in optypes[idx]:
                 updated_circ = False
                 new_data = []
                 for datum in circ.data:

qiskit_aer/backends/qasm_simulator.py

@@ -16,9 +16,8 @@
 import copy
 import logging
 from warnings import warn
-from qiskit.providers import convert_to_target
 from qiskit.providers.options import Options
-from qiskit.providers.backend import BackendV2, BackendV1
+from qiskit.providers.backend import BackendV2
 
 from ..version import __version__
 from ..aererror import AerError
@@ -35,7 +34,6 @@
 
 # pylint: disable=import-error, no-name-in-module, abstract-method
 from .controller_wrappers import aer_controller_execute
-from .name_mapping import NAME_MAPPING
 
 logger = logging.getLogger(__name__)
 
@@ -552,28 +550,9 @@ def from_backend(cls, backend, **options):
             )
             properties = target_to_backend_properties(backend.target)
             target = backend.target
-        elif isinstance(backend, BackendV1):
-            # BackendV1 will be removed in Qiskit 2.0, so we will remove this soon
-            warn(
-                " from_backend using V1 based backend is deprecated as of Aer 0.15"
-                " and will be removed no sooner than 3 months from that release"
-                " date. Please use backends based on V2.",
-                DeprecationWarning,
-                stacklevel=2,
-            )
-            # Get configuration and properties from backend
-            configuration = backend.configuration()
-            properties = copy.copy(backend.properties())
-
-            # Customize configuration name
-            name = configuration.backend_name
-            configuration.backend_name = f"aer_simulator_from({name})"
-
-            target = convert_to_target(configuration, properties, None, NAME_MAPPING)
         else:
             raise TypeError(
-                "The backend argument requires a BackendV2 or BackendV1 object, "
-                f"not a {type(backend)} object"
+                "The backend argument requires a BackendV2 object, " f"not a {type(backend)} object"
             )
         # Use automatic noise model if none is provided
         if "noise_model" not in options:

qiskit_aer/noise/device/parameters.py

@@ -12,6 +12,8 @@
 
 """
 Functions to extract device error parameters from backend properties.
+
+We assume the structure of the class `BackendProperties` in `qiskit-ibm-runtime`.
 """
 
 from numpy import inf

qiskit_aer/noise/noise_model.py

@@ -22,9 +22,7 @@
 
 from qiskit.circuit import QuantumCircuit, Instruction, Delay, Reset
 from qiskit.circuit.library.generalized_gates import PauliGate, UnitaryGate
-from qiskit.providers import QubitProperties
 from qiskit.providers.exceptions import BackendPropertyError
-from qiskit.providers.models.backendproperties import BackendProperties
 from qiskit.transpiler import PassManager
 from qiskit.utils import apply_prefix
 from .device.models import _excited_population, _truncate_t2_value
@@ -381,27 +379,6 @@ def from_backend(
                     UserWarning,
                 )
             dt = backend.dt
-        elif backend_interface_version <= 1:
-            # BackendV1 will be removed in Qiskit 2.0, so we will remove this soon
-            warn(
-                " from_backend using V1 based backend is deprecated as of Aer 0.15"
-                " and will be removed no sooner than 3 months from that release"
-                " date. Please use backends based on V2.",
-                DeprecationWarning,
-                stacklevel=2,
-            )
-            properties = backend.properties()
-            configuration = backend.configuration()
-            basis_gates = configuration.basis_gates
-            all_qubit_properties = [
-                QubitProperties(
-                    t1=properties.t1(q), t2=properties.t2(q), frequency=properties.frequency(q)
-                )
-                for q in range(configuration.num_qubits)
-            ]
-            dt = getattr(configuration, "dt", 0)
-            if not properties:
-                raise NoiseError(f"Qiskit backend {backend} does not have a BackendProperties")
         else:
             raise NoiseError(f"{backend} is not a Qiskit backend")
 
@@ -458,7 +435,7 @@ def from_backend(
     @classmethod
     def from_backend_properties(
         cls,
-        backend_properties: BackendProperties,
+        backend_properties: "BackendProperties",
         gate_error: bool = True,
         readout_error: bool = True,
         thermal_relaxation: bool = True,
@@ -506,10 +483,11 @@ def from_backend_properties(
         Raises:
             NoiseError: If the input backend properties are not valid.
         """
-        if not isinstance(backend_properties, BackendProperties):
-            raise NoiseError(
-                "{} is not a Qiskit backend or" " BackendProperties".format(backend_properties)
-            )
+        for required_field in ["gates", "qubits", "frequency", "t1", "t2"]:
+            if not hasattr(backend_properties, required_field):
+                raise NoiseError(
+                    f"Backend properties are missing the required field '{required_field}'"
+                )
         basis_gates = set()
         for prop in backend_properties.gates:
             basis_gates.add(prop.gate)

releasenotes/notes/qiskit_2_deprecations-35cb57738ca1417e.yaml

@@ -0,0 +1,9 @@
+---
+deprecations:
+  - |
+    Remove the parts of the code that relied on deprecated `qiskit` components that are being removed in Qiskit 2.0::
+      * Everything that uses `convert_to_target` is removed
+      * Usage of `qiskit.pulse` is removed.
+      * Use of `BackendProperties` is removed.
+      * `BackendV1` related code is removed.
+      * Use of `BackendStatus` was removed, resulting in the removal of the :meth:`status` method for the Aer backend.

test/terra/noise/test_device_models.py

@@ -18,7 +18,6 @@
 
 import qiskit
 from qiskit.circuit import library, Reset, Measure, Parameter
-from qiskit.providers import convert_to_target
 from qiskit.transpiler import CouplingMap, Target, QubitProperties, InstructionProperties
 
 if qiskit.__version__.startswith("0."):
@@ -101,25 +100,6 @@ def test_basic_device_gate_errors_from_target_with_non_operational_qubits(self):
         # check if no error is added on cx gate on a qubit pair without T1 and T2 definitions
         self.assertTrue(errors_on_cx[faulty_qubits].ideal())
 
-    def test_basic_device_gate_errors_from_target_and_properties(self):
-        """Test if the device same gate errors are produced both from target and properties"""
-        backend = Fake5QV1()
-        target = convert_to_target(
-            configuration=backend.configuration(),
-            properties=backend.properties(),
-        )
-        errors_from_properties = basic_device_gate_errors(properties=backend.properties())
-        errors_from_target = basic_device_gate_errors(target=target)
-        self.assertEqual(len(errors_from_properties), len(errors_from_target))
-        errors_from_properties_s = sorted(errors_from_properties)
-        errors_from_target_s = sorted(errors_from_target)
-        for err_properties, err_target in zip(errors_from_properties_s, errors_from_target_s):
-            name1, qargs1, err1 = err_properties
-            name2, qargs2, err2 = err_target
-            self.assertEqual(name1, name2)
-            self.assertEqual(tuple(qargs1), qargs2)
-            self.assertEqual(err1, err2)
-
     def test_basic_device_gate_errors_from_target_with_no_t2_value(self):
         """Test if gate errors are successfully created from a target with qubits not reporting T2.
         See https://github.com/Qiskit/qiskit-aer/issues/1896 for the details."""