Qutip-qip

Improvements
------------
- Update qiskit support version to ``0.46.*`` (232)

Bug Fixes
---------
- Remove comments after meaningful statements in QASM reader. (218 by NoriyukiK-1qbit)
- Fix circuit plot error for gates with classical controls when ``reverse_states=False``. (221 by Kevin P. O'Brien)
- Update the RTD configuration file to execute ``create_tutorials_html.py`` (222 reported by Ramyashri Padmanabhakumar)
- Remove the unnecessary use of circuit.propagatos (226)
- Use CSR as default for ``expand_operator`` (227)
- Update the parsing mode for ``read_qasm`` (224 reported by kevinab107)

This release adds two major features and one minor feature to the package.

New features
------------
- **MAJOR** Add Variational Quantum Algorithms in a new module `qutip_qip.vqa`. [Unitary fund microgrant project](https://unitary.fund/posts/vqa_in_qutip.html) (#123)
- **MAJOR** qutip-qip backends for qiskit `qutip_qip.qiskit`. [Google Summer of Code project 2022](https://summerofcode.withgoogle.com/archive/2022/projects/jFfaK3Su) (#155)
- Add class representation of quantum gates. (147)

Documentation
-------------
- Add synced qutip-qip tutorials to documentation on Read the docs (207)

This release fixes a few bugs and adds a minor feature to the `SCQubits` model.

Improvements
------------
- Add DRAG correction for the ``SCQubits`` simulator. Also improve the interpolation for the idling gates for continuous pulse shape. (https://github.com/qutip/qutip-qip/pull/156)

Bug Fixes
---------
- Fix usage of ``rand_unitary`` and ``rand_ket``. (https://github.com/qutip/qutip-qip/pull/163)
- Fix the final time calculation in ``GateCompiler.compile``. (https://github.com/qutip/qutip-qip/pull/162)
- Fix bug for circuit with selected measurement result. (https://github.com/qutip/qutip-qip/pull/167)
- Fix bugs in the analytical pulse shapes. (https://github.com/qutip/qutip-qip/pull/169)
- Fix the swap gate plotting. (https://github.com/qutip/qutip-qip/pull/170) and ( (https://github.com/qutip/qutip-qip/pull/177)
- Filter the measurement probability (https://github.com/qutip/qutip-qip/pull/182)
- Add a default `max_step` based on the circuit time (https://github.com/qutip/qutip-qip/pull/183)

Miscellaneous
-------------
- Fix parsing of package versions in packaging 22. (https://github.com/qutip/qutip-qip/pull/181)

This release adds a few small patches and ensures compatibility with the `dev.major` version of `qutip`.

Improvements
----------------
- Correct the spelling of Hadamard. ([132](https://github.com/qutip/qutip-qip/pull/132))
- Quantum circuits inherit user gates from add_circuit. ([144](https://github.com/qutip/qutip-qip/pull/144))

But Fixes
---------
- Fix Circuit Plotting for non-reversed states. ([137](https://github.com/qutip/qutip-qip/pull/137))
- Export circuit plots as png with dpi. ([139](https://github.com/qutip/qutip-qip/pull/139))
- Fix add_gate behavior when supplied multiple indices. ([142](https://github.com/qutip/qutip-qip/pull/142))

This release includes a revision of the documentation and adds more code examples in the API docstrings.

Bug Fixes
----------
- Remove the check on the initial state dimension in `QubitCircuit` (https://github.com/qutip/qutip-qip/pull/127)

Improvements
------------
- Rewrite the documentation for the pulse-level simulation. (https://github.com/qutip/qutip-qip/pull/121)
- Add more code examples in the docstrings. (https://github.com/qutip/qutip-qip/pull/126)

This release adds a few new features to the pulse-level simulator.

Improvements
------------
- **MAJOR** Add the `Model` class that represents the physical model including hardware parameters, control and drift Hamiltonians and noise objects. (https://github.com/qutip/qutip-qip/pull/105)
- Separate the gate definition from the QubitCircuit.propagators method (https://github.com/qutip/qutip-qip/pull/83)
- Support different pulse shapes. (https://github.com/qutip/qutip-qip/pull/85)
- Use autosummary to generate a summary of API docs. (https://github.com/qutip/qutip-qip/pull/103)
- Improve the scheduling algorithm. (https://github.com/qutip/qutip-qip/pull/105)

Compatibility Note
-----------------
The behaviour of ``Processor.pulses`` changes significantly from version 0.1 to version 0.2. In 0.1, if no control coefficients are added, `pulses` contains a list of partially initialized `Pulse` objects. They include control Hamiltonians but have no coefficients or tlist. This behaviour has changed. From 0.2, the list only includes controls that have non-trivial dynamics. To inspect the available control Hamiltonians, please use `Processor.get_control` and `Processor.get_control_labels`.