From 357983ec8763478bdad424abfeb80ee46105e382 Mon Sep 17 00:00:00 2001
From: Luciano Bello <bel@zurich.ibm.com>
Date: Thu, 23 Nov 2023 16:39:18 +0100
Subject: [PATCH] Remove deprecated `IntegerComparator.num_ancilla_qubits`
 (#11306)

* remove deprecated IntegerComparator.num_ancilla_qubits

* reno
---
 .../circuit/library/arithmetic/integer_comparator.py  | 11 -----------
 ...omparator_num_ancilla_qubits-bd1cff3366c345ae.yaml |  6 ++++++
 2 files changed, 6 insertions(+), 11 deletions(-)
 create mode 100644 releasenotes/notes/5079_IntegerComparator_num_ancilla_qubits-bd1cff3366c345ae.yaml

diff --git a/qiskit/circuit/library/arithmetic/integer_comparator.py b/qiskit/circuit/library/arithmetic/integer_comparator.py
index 699e8c221ff3..1324d512ea6f 100644
--- a/qiskit/circuit/library/arithmetic/integer_comparator.py
+++ b/qiskit/circuit/library/arithmetic/integer_comparator.py
@@ -14,7 +14,6 @@
 """Integer Comparator."""
 
 from __future__ import annotations
-import warnings
 import numpy as np
 
 from qiskit.circuit import QuantumCircuit, QuantumRegister, AncillaRegister
@@ -100,16 +99,6 @@ def geq(self, geq: bool) -> None:
             self._invalidate()
             self._geq = geq
 
-    @property
-    def num_ancilla_qubits(self):
-        """Deprecated. Use num_ancillas instead."""
-        warnings.warn(
-            "The IntegerComparator.num_ancilla_qubits property is deprecated "
-            "as of 0.16.0. It will be removed no earlier than 3 months after the release "
-            "date. You should use the num_ancillas property instead."
-        )
-        return self.num_ancillas
-
     @property
     def num_state_qubits(self) -> int:
         """The number of qubits encoding the state for the comparison.
diff --git a/releasenotes/notes/5079_IntegerComparator_num_ancilla_qubits-bd1cff3366c345ae.yaml b/releasenotes/notes/5079_IntegerComparator_num_ancilla_qubits-bd1cff3366c345ae.yaml
new file mode 100644
index 000000000000..9364ffd605b3
--- /dev/null
+++ b/releasenotes/notes/5079_IntegerComparator_num_ancilla_qubits-bd1cff3366c345ae.yaml
@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    The property ``IntegerComparator.num_ancilla_qubits`` is removed, which was 
+    deprecated in Qiskit 0.23 (released on Oct 2020). Its functionality is fully covered
+    by :attr:`.IntegerComparator.num_ancilla`.