Mitiq

All Changes

- Fix broken links on the website (erkska, gh-400).
- Use cirq v0.9.0 instead of cirq-unstable (karalekas, gh-402).
- Update mitiq.about() (rmlarose, gh-399).
- Refresh the release process documentation (karalekas, gh-392).
- Redesign factories, batch runs in BatchedFactory, fix Qiskit utils tests (rmlarose, andreamari, gh-381).
- Add note on batched executors to docs (rmlarose, gh-405).
- Added Tensorflow Quantum executor to docs (k-m-schultz, gh-348).
- Fix a collection of small build & docs issues (karalekas, gh-410).
- Add optimal QPR decomposition for depolarizing noise (karalekas, gh-371).
- Add PEC basic implementation assuming a decomposition dictionary is given (andreamari, gh-373).
- Make tensorflow requirements optional for docs (karalekas, gh-417).

Thanks to erkska and k-m-schultz for their contributions to this release!

│ Scale method: fold_global │ Improvement factor: 0.3333 │ Improvement factor: 0.9709 │
├────────────────────────────────────┼────────────────────────────┼────────────────────────────┤
│ Technique: ZNE │ ✘ │ ✔ │
│ Factory: Richardson │ Noisy error: 0.03 │ Noisy error: 1.0 │

│ Scale method: fold_global │ Improvement factor: 0.72 │ Improvement factor: 1.0025 │
└────────────────────────────────────┴────────────────────────────┴────────────────────────────┘


**New benchmarking circuits:** `mitiq.benchmarks` now contains a function `generate_random_clifford_t_circuit` which does what it says on the tin.
Special shoutout to new UF team member Farrokh Labib (farlab) for this contribution.

py
from mitiq.benchmarks import generate_random_clifford_t_circuit

clifft = generate_random_clifford_t_circuit(
num_qubits=2,
num_oneq_cliffords=5,
num_twoq_cliffords=5,
num_t_gates=5
)
print(clifft)
0: ──────────────S───T──────H───T───X───T───T─────────────
│ │ │ │ │
1: ───S───T──────────────X──────────────S──────────X───S───


The `Executor.run` method now supports a single circuit instance in addition to a list for ease of use when working with a single circuit.

diff
- executor.run([circuit])
+ executor.run(circuit)


**Faster Tests!** Working on Mitiq has never been easier to develop with a faster (by 36%) test suite.

📓 Documentation

This release contains quite a few documentation improvements, including

1. New workflow images to elucidate the workflow for for using the `mitiq.shadows` module (available [here](https://mitiq.readthedocs.io/en/stable/guide/shadows.html))
2. A reorganized API-doc which should be easier to navigate
3. General clean up of the CDR user guide pages

Commits

- Clarify CDR training docs regarding the use of a markov chain monte carlo (2130) [natestemen]
- Update workflow images in documentation (2034) [purva-thakre]
- 2115 pauli twirling callibration of expectation estimation shadow needs continue (2116) [bdg221]
- Add randomized clifford+T benchmarking circuits. (2118) [farlab]
- Frontend/Backend docs clean up (2124) [natestemen]
- Speed up tests using mocks (2126) [natestemen]
- resolve flaky mirror QV circuit test (2127) [natestemen + misty-w]
- Simplify expectation_estimation_shadow code (2113) [bdg221]
- Refactor calibration logs (2074) [kozhukalov]
- Organize API-doc (2104) [purva-thakre]
- add support for single circuit on exeuctor run method (2099) [emilianog-byte]

📦 Dependency updates

- Update qiskit-ibm-provider requirement from ~=0.7.2 to ~=0.7.3 (2122) [dependabot]
- Update cirq requirement from <1.3.0,>=1.0.0 to >=1.0.0,<1.4.0 (2107) [dependabot]
- Update pennylane requirement from ~=0.32.0 to ~=0.33.1 (2091) [dependabot]
- Update pennylane-qiskit requirement from ~=0.32.0 to ~=0.33.0 (2081) [dependabot]
- Bump stim/stimcirq from 1.12.0 to 1.12.1 (2106) [dependabot]
- Update amazon-braket-sdk requirement from ~=1.59.2 to ~=1.64.1 (2089 + 2094 + 2114 + 2123) [dependabot]
- Update scipy requirement from <=1.11.3,>=1.5.0 to >=1.5.0,<=1.11.4 (2095) [dependabot]

🧑‍💻 Dev Dependency updates

- Bump myst-nb from 0.17.1 to 1.0.0 (2090) [dependabot]
- Bump pandas from 2.1.2 to 2.1.3 (2093) [dependabot]
- Bump matplotlib from 3.8.0 to 3.8.1 (2084) [dependabot]
- Bump isort from 5.12.0 to 5.13.2 (2120 + 2125) [dependabot]
- Bump actions/setup-python from 4 to 5 (2112) [dependabot]

│ Scale method: fold_global │ Improvement factor: 0.5333 │ Improvement factor: 1.0309 │
├────────────────────────────────────┼────────────────────────────┼────────────────────────────┤
│ Technique: ZNE │ ✘ │ ✔ │
│ Factory: Linear │ Noisy error: 0.03 │ Noisy error: 1.0 │

([Full Changelog](https://github.com/unitaryfund/mitiq/compare/v0.40.0...v0.41.0))

Highlights

📓 The Layerwise Richardson Extrapolation **(LRE) user guide is complete**!
The user guide contains information about both the ins and outs of using the implementation, as well as covering the theory behind the technique so you can make judgements about when to apply the technique.
In addition to finishing the user guide, we also have a new tutorial comparing both the performance and overhead needed for LRE and ZNE.
Big thanks to purva-thakre and FarLab for the documentation!

📹 As part of launching LRE we made a **short tutorial video** to showcase the technique, along with how to use it.
Check it out [here](https://www.youtube.com/watch?v=47GWi4h7TWM)!

🧑‍🔬 **First time contributor** jpacold recreated results from [a paper](https://arxiv.org/abs/2211.08318) on phase transitions in the Ising model.
Both the paper authors, and jpacold both used Mitiq's ZNE module to apply error mitigation.
This is both an informative tutorial on turning physics problems into something amenable on a quantum computer, and a class in applying error-mitigation.

✨ Enhancements

- Ensure LRE compatibility with all supported frontends (2547) [natestemen]

🧑🏽‍💻 Developer Improvements

- remove failing test; simplify layerwise ZNE tests (2545) [natestemen]

📞 Call for ideas

We're currently looking into what features we could add to make Mitiq more **noise-aware**.
If you have ideas and features requests in this area, do make a post on the GitHub discussion [here](https://github.com/unitaryfund/mitiq/discussions/2193)!