Merge branch 'main' of github.com:Qiskit/documentation into audit-2.1

Author: kaelynj

.github/ISSUE_TEMPLATE/courses.yaml

@@ -2,7 +2,6 @@ name: (COURSES 🎓) Report a bug/typo or request new content
 description: Report typos, bugs, out-of-date content, broken links, etc. or make a request for new content
 labels: ["content 📄", "course 🎓", "needs triage 🤔"]
 assignees:
-  - jhwatrous
   - livlanes
   - christopherporter1
   - docs-content-team

.github/workflows/notebook-test.yml

@@ -47,6 +47,7 @@ jobs:
           docs/guides/transpiler-stages.ipynb
           docs/guides/represent-quantum-computers.ipynb
           docs/guides/common-parameters.ipynb
+          docs/guides/DAG-representation.ipynb
           """.strip().split("\n")
           import os
           github_output = os.getenv("GITHUB_OUTPUT")

ImageMagick.tar.gz

@@ -0,0 +1,4 @@
+{
+  "name": "qiskit-c",
+  "version": "2.0.3"
+}

docs/api/qiskit-c/2.0/_package.json

@@ -0,0 +1,30 @@
+{
+  "title": "Qiskit SDK C API",
+  "children": [
+    {
+      "title": "API index",
+      "url": "/docs/api/qiskit-c/2.0"
+    },
+    {
+      "title": "QkBitTerm",
+      "url": "/docs/api/qiskit-c/2.0/qk-bit-term"
+    },
+    {
+      "title": "QkExitCode",
+      "url": "/docs/api/qiskit-c/2.0/qk-exit-code"
+    },
+    {
+      "title": "QkObs",
+      "url": "/docs/api/qiskit-c/2.0/qk-obs"
+    },
+    {
+      "title": "QkObsTerm",
+      "url": "/docs/api/qiskit-c/2.0/qk-obs-term"
+    },
+    {
+      "title": "Release notes",
+      "url": "/docs/api/qiskit/release-notes"
+    }
+  ],
+  "collapsed": true
+}

docs/api/qiskit-c/2.0/_toc.json

@@ -0,0 +1,25 @@
+---
+title: Qiskit SDK C API API documentation (v2.0)
+description: Index of all the modules in qiskit-c v2.0.
+---
+
+<span id="qiskit-c-api-qiskit-h" />
+
+# Qiskit C API (`qiskit.h`)
+
+The Qiskit C API is a low level interface to the core data model of Qiskit. It is designed to provide a high performance interface to Qiskit for compiled languages and provides a defined ABI to the internal Rust data model that is used to create the Python API. There are two expected modes of operation for the C API:
+
+*   A standalone shared library for creating and working with Qiskit objects from compiled languages without a runtime dependency on Python, and
+*   For building Python extensions that are using Qiskit but interface directly with the Rust objects from the extension code without using Python for better performance.
+
+To get started, see [Install the Qiskit C API](/docs/guides/install-c-api). To combine the C API with custom Python extensions, see [Extend Qiskit in Python with C](/docs/guides/c-extension-for-python).
+
+As this interface is still new in Qiskit it should be considered experimental and the interface might change between minor version releases.
+
+## Quantum information
+
+*   [QkObs](qk-obs)
+*   [QkObsTerm](qk-obs-term)
+*   [QkBitTerm](qk-bit-term)
+*   [QkExitCode](qk-exit-code)
+

docs/api/qiskit-c/2.0/index.mdx

@@ -0,0 +1,120 @@
+---
+title: QkBitTerm (v2.0)
+description: API reference for QkBitTerm in qiskit-c v2.0
+in_page_toc_min_heading_level: 2
+python_api_type: module
+python_api_name: QkBitTerm
+---
+
+# QkBitTerm
+
+```c
+enum QkBitTerm
+```
+
+An enum that to represent each of the single-qubit alphabet terms enumerated below.
+
+## Values
+
+*   **`QkBitTerm_X`**
+
+    The Pauli $X$ operator.
+
+    Value: 2 (`0b0010`)
+
+*   **`QkBitTerm_Y`**
+
+    The Pauli $Y$ operator.
+
+    Value: 3 (`0b0011`)
+
+*   **`QkBitTerm_Z`**
+
+    The Pauli $Z$ operator.
+
+    Value: 1 (`0b0001`)
+
+*   **`QkBitTerm_Plus`**
+
+    The projector $\lvert +\rangle\langle +\rvert$ to the positive $X$ eigenstate.
+
+    Value: 10 (`0b1010`)
+
+*   **`QkBitTerm_Minus`**
+
+    The projector $\lvert -\rangle\langle -\rvert$ to the negative $X$ eigenstate.
+
+    Value: 6 (`0b0110`)
+
+*   **`QkBitTerm_Right`**
+
+    The projector $\lvert r\rangle\langle r\rvert$ to the positive $Y$ eigenstate.
+
+    Value: 11 (`0b1011`)
+
+*   **`QkBitTerm_Left`**
+
+    The projector $\lvert l\rangle\langle l\rvert$ to the negative $Y$ eigenstate.
+
+    Value: 7 (`0b0111`)
+
+*   **`QkBitTerm_Zero`**
+
+    The projector $\lvert 0\rangle\langle 0\rvert$ to the positive $Z$ eigenstate.
+
+    Value: 9 (`0b1001`)
+
+*   **`QkBitTerm_One`**
+
+    The projector $\lvert 1\rangle\langle 1\rvert$ to the negative $Z$ eigenstate.
+
+    Value: 5 (`0b0101`)
+
+## Representation
+
+The enum is stored as single byte, its elements are represented as unsigned 8-bit integer.
+
+```c
+typedef uint8_t QkBitTerm
+```
+
+<Admonition title="Warning" type="caution">
+  Not all `uint8_t` values are valid bit terms. Passing invalid values is undefined behavior.
+</Admonition>
+
+The numeric structure of these is that they are all four-bit values of which the low two bits are the (phase-less) symplectic representation of the Pauli operator related to the object, where the low bit denotes a contribution by $Z$ and the second lowest a contribution by $X$, while the upper two bits are `00` for a Pauli operator, `01` for the negative-eigenstate projector, and `10` for the positive-eigenstate projector.
+
+## Functions
+
+### qk\_bitterm\_label
+
+<Function id="qk_bitterm_label" signature="uint8_t qk_bitterm_label(QkBitTerm bit_term)">
+  Get the label for a bit term.
+
+  <span id="group__QkBitTerm_1autotoc_md46" />
+
+  #### Example
+
+  ```c
+  QkBitTerm bit_term = QkBitTerm_Y;
+  // cast the uint8_t to char
+  char label = qk_bitterm_label(bit_term);
+  ```
+
+  <span id="group__QkBitTerm_1autotoc_md47" />
+
+  #### Safety
+
+  <span id="group__QkBitTerm_1autotoc_md47" />
+
+  The behavior is undefined if `bit_term` is not a valid `uint8_t` value of a `QkBitTerm`.
+
+  **Parameters**
+
+  **bit\_term** – The bit term.
+
+  **Returns**
+
+  The label as `uint8_t`, which can be cast to `char` to obtain the character.
+</Function>
+

docs/api/qiskit-c/2.0/qk-bit-term.mdx

@@ -0,0 +1,60 @@
+---
+title: QkExitCode (v2.0)
+description: API reference for QkExitCode in qiskit-c v2.0
+in_page_toc_min_heading_level: 2
+python_api_type: module
+python_api_name: QkExitCode
+---
+
+# QkExitCode
+
+```c
+enum QkExitCode
+```
+
+Function exit codes.
+
+## Values
+
+*   **`QkExitCode_Success`**
+
+    Success.
+
+    Value: 0
+
+*   **`QkExitCode_CInputError`**
+
+    Error related to data input.
+
+    Value: 100
+
+*   **`QkExitCode_NullPointerError`**
+
+    Unexpected null pointer.
+
+    Value: 101
+
+*   **`QkExitCode_AlignmentError`**
+
+    Pointer is not aligned to expected data.
+
+    Value: 102
+
+*   **`QkExitCode_IndexError`**
+
+    Index out of bounds.
+
+    Value: 103
+
+*   **`QkExitCode_ArithmeticError`**
+
+    Error related to arithmetic operations or similar.
+
+    Value: 200
+
+*   **`QkExitCode_MismatchedQubits`**
+
+    Mismatching number of qubits.
+
+    Value: 201
+

docs/api/qiskit-c/2.0/qk-exit-code.mdx

@@ -0,0 +1,101 @@
+---
+title: QkObsTerm (v2.0)
+description: API reference for QkObsTerm in qiskit-c v2.0
+in_page_toc_min_heading_level: 2
+python_api_type: module
+python_api_name: QkObsTerm
+---
+
+# QkObsTerm
+
+This is a group of functions for interacting with an opaque (Rust-space) SparseTerm instance.
+
+## Data types
+
+### QkObsTerm
+
+<Class id="QkObsTerm" signature="struct QkObsTerm">
+  A term in a `QkObs`.
+
+  This contains the coefficient (`coeff`), the number of qubits of the observable (`num_qubits`) and pointers to the `bit_terms` and `indices` arrays, which have length `len`. It’s the responsibility of the user that the data is coherent, see also the below section on safety.
+
+  <span id="structQkObsTerm_1autotoc_md2" />
+
+  #### Safety
+
+  <span id="structQkObsTerm_1autotoc_md2" />
+
+  *   `bit_terms` must be a non-null, aligned pointer to `len` elements of type `QkBitTerm`.
+  *   `indices` must be a non-null, aligned pointer to `len` elements of type `uint32_t`.
+
+  #### QkComplex64 coeff
+
+  <Attribute id="coeff">
+    The coefficient of the observable term.
+  </Attribute>
+
+  #### uintptr\_t len
+
+  <Attribute id="len">
+    Length of the `bit_terms` and `indices` arrays.
+  </Attribute>
+
+  #### QkBitTerm \*bit\_terms
+
+  <Attribute id="bit_terms">
+    A non-null, aligned pointer to `len` elements of type `QkBitTerm`.
+  </Attribute>
+
+  #### uint32\_t \*indices
+
+  <Attribute id="indices">
+    A non-null, aligned pointer to `len` elements of type `uint32_t`.
+  </Attribute>
+
+  #### uint32\_t num\_qubits
+
+  <Attribute id="num_qubits">
+    The number of qubits the observable term is defined on.
+  </Attribute>
+</Class>
+
+## Functions
+
+### qk\_obsterm\_str
+
+<Function id="qk_obsterm_str" signature="char *qk_obsterm_str(const QkObsTerm *term)">
+  Return a string representation of the sparse term.
+
+  <span id="group__QkObsTerm_1autotoc_md44" />
+
+  #### Example
+
+  ```c
+  QkObs *obs = qk_obs_identity(100);
+  QkObsTerm term;
+  qk_obs_term(obs, 0, &term);
+  char *string = qk_obsterm_str(&term);
+  qk_str_free(string);
+  ```
+
+  <span id="group__QkObsTerm_1autotoc_md45" />
+
+  #### Safety
+
+  <span id="group__QkObsTerm_1autotoc_md45" />
+
+  Behavior is undefined `term` is not a valid, non-null pointer to a `QkObsTerm`.
+
+  The string must not be freed with the normal C free, you must use `qk_str_free` to free the memory consumed by the String. Not calling `qk_str_free` will lead to a memory leak.
+
+  Do not change the length of the string after it’s returned, although values can be mutated.
+
+  **Parameters**
+
+  **term** – A pointer to the term.
+
+  **Returns**
+
+  The function exit code. This is `>0` if reading the term failed.
+</Function>
+