Suppress warnings from Qiskit Nature

circuit_knitting/forging/__init__.py

@@ -45,6 +45,16 @@
     EntanglementForgingGroundStateSolver,
 )
 from .cholesky_decomposition import cholesky_decomposition, convert_cholesky_operator
+from qiskit_nature import settings
+
+# From now forward, the entanglement forging module requires that SparsePauliOp
+# be used rather than PauliSumOp, as the latter is deprecated in Qiskit Terra 0.24.
+# However, Qiskit Nature still is not expected to change this default until Qiskit
+# Nature 0.7. Here, we modify the global state to opt into the new behavior early.
+# Unfortunately, this means that any code that calls Qiskit Nature in the same
+# process as entanglement forging will need to be updated to use SparsePauliOp as well.
+
+settings.use_pauli_sum_op = False
 
 __all__ = [
     "EntanglementForgingAnsatz",

circuit_knitting/forging/cholesky_decomposition.py

@@ -18,10 +18,10 @@
 
 import numpy as np
 
-from qiskit.opflow import PauliSumOp
 from qiskit.quantum_info import Pauli
+from qiskit.quantum_info.operators.symplectic import SparsePauliOp
 from qiskit_nature.second_q.problems import ElectronicStructureProblem
-from qiskit_nature.second_q.mappers import QubitConverter, JordanWignerMapper
+from qiskit_nature.second_q.mappers import JordanWignerMapper
 from qiskit_nature.second_q.operators import (
     FermionicOp,
     PolynomialTensor,
@@ -36,8 +36,8 @@
 
 
 def get_cholesky_op(
-    l_op: np.ndarray, g: int, converter: QubitConverter, opname: str
-) -> PauliSumOp:
+    l_op: np.ndarray, g: int, converter: JordanWignerMapper, opname: str
+) -> SparsePauliOp:
     """
     Convert a two-body term into a cholesky operator.
 
@@ -52,7 +52,7 @@ def get_cholesky_op(
     """
     pt = PolynomialTensor({"+-": l_op[:, :, g]})
     fer_op = FermionicOp.from_polynomial_tensor(pt)
-    cholesky_op = converter.convert(fer_op)
+    cholesky_op = converter.map(fer_op)
     cholesky_op._name = opname + "_chol" + str(g)
 
     return cholesky_op
@@ -62,7 +62,7 @@ def cholesky_decomposition(
     problem: ElectronicStructureProblem,
     mo_coeff: np.ndarray | None = None,
     orbitals_to_reduce: Sequence[int] | None = None,
-) -> tuple[list[PauliSumOp], float]:
+) -> tuple[list[SparsePauliOp], float]:
     """
     Construct the decomposed Hamiltonian from an input ``ElectronicStructureProblem``.
 
@@ -124,14 +124,14 @@ def cholesky_decomposition(
 
 
 def convert_cholesky_operator(
-    operator: list[PauliSumOp],
+    operator: list[SparsePauliOp],
     ansatz: EntanglementForgingAnsatz,
 ) -> EntanglementForgingOperator:
     """
-    Convert the Cholesky operator (List[PauliSumOp]) into the entanglement forging format.
+    Convert the Cholesky operator (List[SparsePauliOp]) into the entanglement forging format.
 
     Args:
-        operator: A `List[PauliSumOp]` containing the single-body Hamiltonian followed
+        operator: A `List[SparsePauliOp]` containing the single-body Hamiltonian followed
             by the Cholesky operators
             shape: [single-body hamiltonian, cholesky_0, ..., cholesky_N]
         ansatz: The ansatz for which to compute expectation values of operator. The
@@ -153,11 +153,7 @@ def convert_cholesky_operator(
     tensor_paulis = set()
     superpos_paulis = set()
     paulis_each_op = [
-        {
-            label: weight
-            for label, weight in op.primitive.to_list()
-            if np.abs(weight) > 0
-        }
+        {label: weight for label, weight in op.to_list() if np.abs(weight) > 0}
         for op in [op1] + list(cholesky_ops)
     ]
 
@@ -242,7 +238,7 @@ def _get_fermionic_ops_with_cholesky(
     occupied_orbitals_to_reduce: np.ndarray | None = None,
     virtual_orbitals_to_reduce: np.ndarray | None = None,
     epsilon_cholesky: float = 1e-10,
-) -> tuple[PauliSumOp, list[PauliSumOp], float, np.ndarray, np.ndarray,]:
+) -> tuple[SparsePauliOp, list[SparsePauliOp], float, np.ndarray, np.ndarray,]:
     r"""
     Decompose the Hamiltonian operators into a form appropriate for entanglement forging.
 
@@ -335,11 +331,10 @@ def _get_fermionic_ops_with_cholesky(
     if halve_transformed_h2:
         h2 /= 2  # type: ignore
 
-    converter = QubitConverter(JordanWignerMapper())
+    converter = JordanWignerMapper()
     pt = PolynomialTensor({"+-": h1, "++--": to_physicist_ordering(h2)})
     fer_op = FermionicOp.from_polynomial_tensor(pt)
-    qubit_op = converter.convert(fer_op)
-
+    qubit_op = converter.map(fer_op)
     qubit_op._name = opname + "_onebodyop"
 
     cholesky_ops = [

circuit_knitting/forging/entanglement_forging_ground_state_solver.py

@@ -33,7 +33,7 @@
     ElectronicBasis,
 )
 from qiskit_ibm_runtime import QiskitRuntimeService, Options
-from qiskit.opflow import PauliSumOp
+from qiskit.quantum_info.operators.symplectic import SparsePauliOp
 
 from .entanglement_forging_ansatz import EntanglementForgingAnsatz
 from .entanglement_forging_knitter import EntanglementForgingKnitter
@@ -363,7 +363,7 @@ def evaluate_eigenvalue(parameters: Sequence[float]) -> float:
     def get_qubit_operators(
         self,
         problem: ElectronicStructureProblem,
-    ) -> list[PauliSumOp]:
+    ) -> list[SparsePauliOp]:
         """Construct decomposed qubit operators from an ``ElectronicStructureProblem``.
 
         Args:

pyproject.toml

@@ -28,7 +28,7 @@ requires-python = ">=3.8"
 dependencies = [
     "qiskit-aer>=0.12.0",
     "qiskit-terra>=0.24.0",
-    "qiskit-nature>=0.5.2",
+    "qiskit-nature>=0.6.0",
     "qiskit-ibm-runtime>=0.9.2",
 ]
 
@@ -86,7 +86,6 @@ notebook-dependencies = [
     "matplotlib",
     "ipywidgets",
     "pylatexenc",
-    "qiskit-nature<0.6.0",
 ]
 
 [project.urls]

tools/extremal-python-dependencies.py

@@ -21,7 +21,7 @@ def mapfunc_dev(dep):
     """Load the development version(s) of certain Qiskit-related packages"""
     # https://peps.python.org/pep-0440/#direct-references
     return re.sub(
-        r"^(qiskit-(?:terra|ibm-runtime)).*$",
+        r"^(qiskit-(?:terra|nature|ibm-runtime)).*$",
         r"\1 @ git+https://github.com/Qiskit/\1.git",
         dep,
     )

tox.ini

@@ -37,7 +37,7 @@ extras =
   nbtest
   notebook-dependencies
 commands =
-  pytest --nbmake --nbmake-timeout=3000 {posargs} docs/
+  pytest --nbmake --nbmake-timeout=3000 {posargs} docs/ --ignore=docs/entanglement_forging/tutorials/tutorial_2_forging_with_quantum_serverless.ipynb
 
 [testenv:coverage]
 basepython = python3.10