Exposing layer_noise_model option (#1858)

Co-authored-by: Christopher J. Wood <[email protected]>

docs/apidocs/index.rst

@@ -9,6 +9,7 @@ qiskit-ibm-runtime API reference
 
    runtime_service
    noise_learner
+   noise_learner_result
    options
    transpiler
    qiskit_ibm_runtime.transpiler.passes.scheduling

docs/apidocs/noise_learner_result.rst

@@ -0,0 +1,4 @@
+.. automodule:: qiskit_ibm_runtime.utils.noise_learner_result
+   :no-members:
+   :no-inherited-members:
+   :no-special-members:

qiskit_ibm_runtime/options/resilience_options.py

@@ -12,11 +12,12 @@
 
 """Resilience options."""
 
-from typing import Literal, Union
+from typing import List, Literal, Union
 from dataclasses import asdict
 
 from pydantic import model_validator, Field
 
+from ..utils.noise_learner_result import LayerError
 from .utils import Unset, UnsetType, Dict, primitive_dataclass
 from .measure_noise_learning_options import MeasureNoiseLearningOptions
 from .zne_options import ZneOptions
@@ -65,6 +66,12 @@ class ResilienceOptionsV2:
 
         layer_noise_learning: Layer noise learning options.
             See :class:`LayerNoiseLearningOptions` for all options.
+
+        layer_noise_model: A list of :class:`LayerError` objects.
+            If set, all the mitigation strategies that require noise data (e.g., PEC and PEA)
+            skip the noise learning stage, and instead gather the required information from
+            ``layer_noise_model``. Layers whose information is missing in ``layer_noise_model``
+            are treated as noiseless and their noise is not mitigated.
     """
 
     measure_mitigation: Union[UnsetType, bool] = Unset
@@ -78,6 +85,7 @@ class ResilienceOptionsV2:
     layer_noise_learning: Union[LayerNoiseLearningOptions, Dict] = Field(
         default_factory=LayerNoiseLearningOptions
     )
+    layer_noise_model: Union[UnsetType, List[LayerError]] = Unset
 
     @model_validator(mode="after")
     def _validate_options(self) -> "ResilienceOptionsV2":

qiskit_ibm_runtime/utils/noise_learner_result.py

@@ -10,7 +10,17 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-"""NoiseLearner result class"""
+"""
+==================================================================================
+NoiseLearner result classes (:mod:`qiskit_ibm_runtime.utils.noise_learner_result`)
+==================================================================================
+
+.. autosummary::
+   :toctree: ../stubs/
+
+   PauliLindbladError
+   LayerError
+"""
 
 from __future__ import annotations
 

release-notes/unreleased/1858.feat.rst

@@ -0,0 +1,3 @@
+``ResilienceOptionsV2`` has a new field ``layer_noise_model``. When this field is set, all the
+mitigation strategies that require noise data skip the noise learning stage, and instead gather
+the required information from ``layer_noise_model``.  

test/integration/test_noise_learner.py

@@ -17,12 +17,11 @@
 
 from qiskit.circuit import QuantumCircuit
 from qiskit.providers.jobstatus import JobStatus
-from qiskit.compiler import transpile
 
-from qiskit_ibm_runtime import RuntimeJob, Session
+from qiskit_ibm_runtime import RuntimeJob, Session, EstimatorV2
 from qiskit_ibm_runtime.noise_learner import NoiseLearner
 from qiskit_ibm_runtime.utils.noise_learner_result import PauliLindbladError, LayerError
-from qiskit_ibm_runtime.options import NoiseLearnerOptions
+from qiskit_ibm_runtime.options import NoiseLearnerOptions, EstimatorOptions
 
 from ..decorators import run_integration_test
 from ..ibm_test_case import IBMIntegrationTestCase
@@ -39,12 +38,12 @@ def setUp(self) -> None:
             raise SkipTest("test_eagle not available in this environment")
 
         c1 = QuantumCircuit(2)
-        c1.cx(0, 1)
+        c1.ecr(0, 1)
 
         c2 = QuantumCircuit(3)
-        c2.cx(0, 1)
-        c2.cx(1, 2)
-        c2.cx(0, 1)
+        c2.ecr(0, 1)
+        c2.ecr(1, 2)
+        c2.ecr(0, 1)
 
         self.circuits = [c1, c2]
 
@@ -65,10 +64,9 @@ def test_with_default_options(self, service):  # pylint: disable=unused-argument
         options = NoiseLearnerOptions()
         learner = NoiseLearner(mode=backend, options=options)
 
-        circuits = transpile(self.circuits, backend=backend)
-        job = learner.run(circuits)
+        job = learner.run(self.circuits)
 
-        self._verify(job, self.default_input_options)
+        self._verify(job, self.default_input_options, 3)
 
     @run_integration_test
     def test_with_non_default_options(self, service):  # pylint: disable=unused-argument
@@ -80,43 +78,12 @@ def test_with_non_default_options(self, service):  # pylint: disable=unused-argu
         options.layer_pair_depths = [0, 1]
         learner = NoiseLearner(mode=backend, options=options)
 
-        circuits = transpile(self.circuits, backend=backend)
-        job = learner.run(circuits)
+        job = learner.run(self.circuits)
 
         input_options = deepcopy(self.default_input_options)
         input_options["max_layers_to_learn"] = 1
         input_options["layer_pair_depths"] = [0, 1]
-        self._verify(job, input_options)
-
-    @run_integration_test
-    def test_in_session(self, service):
-        """Test noise learner when used within a session."""
-        backend = self.backend
-
-        options = NoiseLearnerOptions()
-        options.max_layers_to_learn = 1
-        options.layer_pair_depths = [0, 1]
-
-        input_options = deepcopy(self.default_input_options)
-        input_options["max_layers_to_learn"] = 1
-        input_options["layer_pair_depths"] = [0, 1]
-
-        circuits = transpile(self.circuits, backend=backend)
-
-        with Session(service, backend) as session:
-            options.twirling_strategy = "all"
-            learner1 = NoiseLearner(mode=session, options=options)
-            job1 = learner1.run(circuits)
-
-            input_options["twirling_strategy"] = "all"
-            self._verify(job1, input_options)
-
-            options.twirling_strategy = "active-circuit"
-            learner2 = NoiseLearner(mode=session, options=options)
-            job2 = learner2.run(circuits)
-
-            input_options["twirling_strategy"] = "active-circuit"
-            self._verify(job2, input_options)
+        self._verify(job, input_options, 1)
 
     @run_integration_test
     def test_with_no_layers(self, service):  # pylint: disable=unused-argument
@@ -127,20 +94,52 @@ def test_with_no_layers(self, service):  # pylint: disable=unused-argument
         options.max_layers_to_learn = 0
         learner = NoiseLearner(mode=backend, options=options)
 
-        circuits = transpile(self.circuits, backend=backend)
-        job = learner.run(circuits)
+        job = learner.run(self.circuits)
 
         self.assertEqual(job.result().data, [])
 
         input_options = deepcopy(self.default_input_options)
         input_options["max_layers_to_learn"] = 0
-        self._verify(job, input_options)
+        self._verify(job, input_options, 0)
+
+    @run_integration_test
+    def test_learner_plus_estimator(self, service):  # pylint: disable=unused-argument
+        """Test feeding noise learner data to estimator."""
+        backend = self.backend
+
+        options = EstimatorOptions()
+        options.resilience.zne_mitigation = True  # pylint: disable=assigning-non-slot
+        options.resilience.zne.amplifier = "pea"
+        options.resilience.layer_noise_learning.layer_pair_depths = [0, 1]
 
-    def _verify(self, job: RuntimeJob, expected_input_options: dict) -> None:
+        pubs = [(c, "Z" * c.num_qubits) for c in self.circuits]
+
+        with Session(service, backend) as session:
+            learner = NoiseLearner(mode=session, options=options)
+            learner_job = learner.run(self.circuits)
+            noise_model = learner_job.result()
+            self.assertEqual(len(noise_model), 3)
+
+            estimator = EstimatorV2(mode=session, options=options)
+            estimator.options.resilience.layer_noise_model = noise_model
+
+            estimator_job = estimator.run(pubs)
+            result = estimator_job.result()
+
+            noise_model_metadata = result.metadata["resilience"]["layer_noise_model"]
+            for x, y in zip(noise_model, noise_model_metadata):
+                self.assertEqual(x.circuit, y.circuit)
+                self.assertEqual(x.qubits, y.qubits)
+                self.assertEqual(x.error.generators, y.error.generators)
+                self.assertEqual(x.error.rates.tolist(), y.error.rates.tolist())
+
+    def _verify(self, job: RuntimeJob, expected_input_options: dict, n_results: int) -> None:
         job.wait_for_final_state()
         self.assertEqual(job.status(), JobStatus.DONE, job.error_message())
 
         result = job.result()
+        self.assertEqual(len(result), n_results)
+
         for datum in result.data:
             circuit = datum.circuit
             qubits = datum.qubits