Mitiq

Summary

This release adds new getter methods for fit errors, extrapolation curves, etc. in ZNE factory objects as well as
custom types for noisy operations, noisy bases, and decompositions in PEC. It also includes small updates and fixes
to the documentation, seeding options for PEC sampling functions, and bug fixes for a few non-deterministic test failures.

All Changes

- Add reference to review paper in docs (willzeng, gh-423).
- Add unitary folding API to RTD (rmlarose, gh-429).
- Add theory subsection on PEC in docs (elmandouh, gh-428).
- Fix small typo in documentation function name (nathanshammah, gh-435).
- Seed Qiskit simulator to fix non-deterministic test failure (rmlarose, gh-425).
- Fix formatting typo and include hyperlinks to documentation objects (nathanshammah, gh-438).
- Remove error in docs testing without tensorflow (nathanshammah, gh-439).
- Add seed to PEC functions (rmlarose, gh-432).
- Consolidate functions to generate randomized benchmarking circuits in different platforms, and clean up pyquil utils (rmlarose, gh-426).
- Add new get methods (for fit errors, extrapolation curve, etc.) to Factory objects (crazy4pi314, andreamari, gh-403).
- Update notebook version in requirements to resolve vulnerability found by security bot.(nathanshammah, gh-445).
- Add brief description of noise and error mitigtation to readme (rmlarose, gh-422).
- Fix broken links in documentation (purva-thakre, gh-448).
- Link to stable RTD instead of latest RTD in readme (rmlarose, gh-449).
- Add option to automatically deduce the number of samples in PEC (andreamari, gh-451).
- Fix PEC sampling bug (rmlarose, gh-453).
- Add types for PEC (rmlarose, gh-408).
- Add warning for large samples in PEC (sid1993, gh-459).
- Seed a PEC test to avoid non-deterministic failure (andreamari, gh-460).
- Update contributing docs (purva-thakre, gh-465).

Summary

Factories now support "batched" executors, meaning that when a backend allows
for the batch execution of a collection of quantum circuits, factories can now
leverage that functionality. In addition, the main focus of this release was
implementing probabilistic error cancellation (PEC), which was introduced in
[Temme2017][temme2017] as a method for quantum error mitigation. We completed
a first draft of the major components in the PEC workflow, and in the next
release plan to demonstrate the full end-to-end operation of the new technique.

Announcements

The preprint for Mitiq is live on the arXiv [here][arxiv]!

Summary

This release centered on source code reorganization and documentation, as well
as wrapping up some holdovers from the initial public release. In addition, the
team began investigating probabilistic error cancellation (PEC), which will be the
main focus of the following release.

All Changes

- Re-organize scaling code into its own module (rmlarose, gh-338).
- Add BibTeX snippet for [arXiv citation][arxiv] (karalekas, gh-351).
- Fix broken links in PR template (rmlarose, gh-359).
- Add limitations of ZNE section to docs (rmlarose, gh-361).
- Add static extrapolate method to all factories (andreamari, gh-352).
- Removes barriers in conversions from a Qiskit circuit (rmlarose, gh-362).
- Add arXiv badge to readme header (nathanshammah, gh-376).
- Add note on shot list in factory docs (rmlarose, gh-375).
- Spruce up the README a bit (karalekas, gh-383).
- Make mypy checking stricter (karalekas, gh-380).
- Add pyQuil executor examples and benchmarking circuits (karalekas, gh-339).

Summary

This marks the first public release of Mitiq on a stable version.

All Changes

- Add static extrapolate method to all factories (andreamari, gh-352).
- Add the `angle` module for parameter noise scaling (yhindy, gh-288).
- Add to the documentation instructions for maintainers to make a new release (nathanshammah, gh-332).
- Add basic compilation facilities, don't relabel qubits (karalekas, gh-324).
- Update readme (rmlarose, gh-330).
- Add mypy type checking to CI, resolve existing issues (karalekas, gh-326).
- Add readthedocs badge to readme (nathanshammah, gh-329).
- Add change log as markdown file (nathanshammah, gh-328).
- Add documentation on mitigating the energy landscape for QAOA MaxCut on two qubits (rmlarose, gh-241).
- Simplify inverse gates before conversion to QASM (andreamari, gh-283).
- Restructure library with `zne/` subpackage, modules renaming (nathanshammah, gh-298).
- [Bug Fix] Fix minor problems in executors documentation (andreamari, gh-292).
- Add better link to docs and more detailed features (andreamari, gh-306).
- [Bug Fix] Fix links and author list in README (willzeng, gh-302).
- Add new sections and more explanatory titles to the documentation's guide (nathanshammah, gh-285).
- Store optimal parameters after calling reduce in factories (rmlarose, gh-318).
- Run CI on all commits in PRs to master and close 316 (karalekas, gh-325).
- Add Unitary Fund logo to the documentation html and close 297 (nathanshammah, gh-323).
- Add circuit conversion error + tests (rmlarose, gh-321).
- Make test file names unique (rmlarose, gh-319).
- Update package version from v. 0.1a2, released, to 0.10dev (nathanshammah, gh-314).

- **Initial release (internal).**

[Github]: https://github.com/unitaryfund/mitiq