Fix doc format in circuit library (Qiskit#14988) (Qiskit#14992)

* fix references

* consistent circuit lib

* remove dangling "Create new thing" from inits

* Apply suggestions from code review



* more headers done right

* review comments

- consistent indentation
- missed some boldfaces
- fix R,U,U3 argument docs

* tackle the U docs

* missed some **

---------


(cherry picked from commit d6a1706)

Co-authored-by: Julien Gacon <[email protected]>
Co-authored-by: Jake Lishman <[email protected]>

Author: 3 people

qiskit/circuit/gate.py

@@ -32,10 +32,9 @@ def __init__(
         params: list,
         label: str | None = None,
     ) -> None:
-        """Create a new gate.
-
+        """
         Args:
-            name: The Qobj name of the gate.
+            name: The name of the gate.
             num_qubits: The number of qubits the gate acts on.
             params: A list of parameters.
             label: An optional label for the gate.

qiskit/circuit/instruction.py

@@ -58,8 +58,7 @@ class Instruction(Operation):
     _standard_gate = None
 
     def __init__(self, name, num_qubits, num_clbits, params, label=None):
-        """Create a new instruction.
-
+        """
         .. deprecated:: 1.3
            The parameters ``duration`` and ``unit`` are deprecated since
            Qiskit 1.3, and they will be removed in 2.0 or later.

qiskit/circuit/library/__init__.py

@@ -770,7 +770,8 @@
 :class:`~qiskit.circuit.library.CXGate`,
 and :class:`~qiskit.circuit.library.CCXGate` (Toffoli) gates.
 
-**Reference:**
+References:
+
 Maslov, D. and Dueck, G. W. and Miller, D. M.,
 Techniques for the synthesis of reversible Toffoli networks, 2007
 http://dx.doi.org/10.1145/1278349.1278355

qiskit/circuit/library/arithmetic/adders/cdkm_ripple_carry_adder.py

@@ -90,7 +90,7 @@ class CDKMRippleCarryAdder(Adder):
         :class:`.FullAdderGate`: A generic inplace adder, with a carry-in bit. This
             is functionally equivalent to ``kind="full"``.
 
-    **References:**
+    References:
 
     [1] Cuccaro et al., A new quantum ripple-carry addition circuit, 2004.
     `arXiv:quant-ph/0410184 <https://arxiv.org/pdf/quant-ph/0410184.pdf>`_

qiskit/circuit/library/arithmetic/adders/draper_qft_adder.py

@@ -57,7 +57,7 @@ class DraperQFTAdder(Adder):
         :class:`.AdderGate`: A generic inplace adder. This
             is functionally equivalent to ``kind="half"``.
 
-    **References:**
+    References:
 
     [1] T. G. Draper, Addition on a Quantum Computer, 2000.
     `arXiv:quant-ph/0008033 <https://arxiv.org/pdf/quant-ph/0008033.pdf>`_

qiskit/circuit/library/arithmetic/adders/vbe_ripple_carry_adder.py

@@ -66,7 +66,7 @@ class VBERippleCarryAdder(Adder):
         :class:`.FullAdderGate`: A generic inplace adder, with a carry-in bit. This
             is functionally equivalent to ``kind="full"``.
 
-    **References:**
+    References:
 
     [1] Vedral et al., Quantum Networks for Elementary Arithmetic Operations, 1995.
     `arXiv:quant-ph/9511018 <https://arxiv.org/pdf/quant-ph/9511018.pdf>`_

qiskit/circuit/library/arithmetic/functional_pauli_rotations.py

@@ -25,8 +25,7 @@ class FunctionalPauliRotations(BlueprintCircuit, ABC):
     def __init__(
         self, num_state_qubits: Optional[int] = None, basis: str = "Y", name: str = "F"
     ) -> None:
-        r"""Create a new functional Pauli rotation circuit.
-
+        r"""
         Args:
             num_state_qubits: The number of qubits representing the state :math:`|x\rangle`.
             basis: The kind of Pauli rotation to use. Must be 'X', 'Y' or 'Z'.

qiskit/circuit/library/arithmetic/integer_comparator.py

@@ -47,8 +47,7 @@ def __init__(
         geq: bool = True,
         name: str = "cmp",
     ) -> None:
-        """Create a new fixed value comparator circuit.
-
+        """
         Args:
             num_state_qubits: Number of state qubits. If this is set it will determine the number
                 of qubits required for the circuit.

qiskit/circuit/library/arithmetic/linear_amplitude_function.py

@@ -69,13 +69,11 @@ class LinearAmplitudeFunction(QuantumCircuit):
 
     References:
 
-        [1]: Woerner, S., & Egger, D. J. (2018).
-             Quantum Risk Analysis.
-             `arXiv:1806.06893 <http://arxiv.org/abs/1806.06893>`_
+    [1] Woerner, S., & Egger, D. J. (2018). Quantum Risk Analysis.
+    `arXiv:1806.06893 <http://arxiv.org/abs/1806.06893>`_
 
-        [2]: Gacon, J., Zoufal, C., & Woerner, S. (2020).
-             Quantum-Enhanced Simulation-Based Optimization.
-             `arXiv:2005.10780 <http://arxiv.org/abs/2005.10780>`_
+    [2] Gacon, J., Zoufal, C., & Woerner, S. (2020). Quantum-Enhanced Simulation-Based Optimization.
+    `arXiv:2005.10780 <http://arxiv.org/abs/2005.10780>`_
     """
 
     @deprecate_func(
@@ -229,13 +227,13 @@ class LinearAmplitudeFunctionGate(Gate):
 
     References:
 
-        [1]: Woerner, S., & Egger, D. J. (2018).
-             Quantum Risk Analysis.
-             `arXiv:1806.06893 <http://arxiv.org/abs/1806.06893>`_
+    [1] Woerner, S., & Egger, D. J. (2018).
+    Quantum Risk Analysis.
+    `arXiv:1806.06893 <http://arxiv.org/abs/1806.06893>`_
 
-        [2]: Gacon, J., Zoufal, C., & Woerner, S. (2020).
-             Quantum-Enhanced Simulation-Based Optimization.
-             `arXiv:2005.10780 <http://arxiv.org/abs/2005.10780>`_
+    [2] Gacon, J., Zoufal, C., & Woerner, S. (2020).
+    Quantum-Enhanced Simulation-Based Optimization.
+    `arXiv:2005.10780 <http://arxiv.org/abs/2005.10780>`_
     """
 
     def __init__(

qiskit/circuit/library/arithmetic/linear_pauli_rotations.py

@@ -58,8 +58,7 @@ def __init__(
         basis: str = "Y",
         name: str = "LinRot",
     ) -> None:
-        r"""Create a new linear rotation circuit.
-
+        r"""
         Args:
             num_state_qubits: The number of qubits representing the state :math:`|x\rangle`.
             slope: The slope of the controlled rotation.