v0.23.0

Changelog

Version 0.23.0

The main improvements introduced in this release are:

• A significant refactoring of the Mitiq calibration module. We generalized the Settings
  object, which is now able to generate a more general list of BenchmarkProblem objects (wrapping circuits and ideal results) and a list of Strategy objects
  representing the error mitigation strategies to compare. We also improved how the optimal Strategy is determined. Specifically, we now average over BenchmarkProblems to reduce fluctuations and spurious results.
  We remark that the mitiq.calibration module is very new and quickly evolving. Therefore further significant breaking changes are likely to happen in future releases.

• A non-trivial refactoring of the REM module. We changed the underlying workflow of the technique which is now applied directly to executors, instead of applying REM during the evaluation of expectation values. Expectation values can still be mitigated as usual with execute_with_rem but mitigated executors can now return raw MeasurementResult objects (bitstrings).

• We also significantly extended the REM documentation with new and informative sections. Special thanks to @amirebrahimi and @nickdgardner for their high-quality and useful contributions!

• We now have 2 tutorials focused on digital dynamical decoupling (DDD)---one for Cirq and one for Qiskit---both showing an improvement for a theoretical highly-correlated noise model. Moreover, the Qiskit tutorial on DDD is a useful starting point for testing the technique on real hardware.

All changes

• Use closest probability distribution in REM (#1688) [@andreamari]
• REM: Write-up third section of docs (#1693) [@nickdgardner]
• Improve calibration method parameter selection (#1682) [@Misty-W]
• Add References about REM (#1691) [@nathanshammah]
• REM: mitigate executors as a first step and expectation values at a second step. (#1678) [@andreamari]
• Draft for glossary of QEM concepts in docs (#1647) [@nickdgardner]
• myst -> md (#1689) [@natestemen]
• use executor.run in rem docs (#1690) [@andreamari]
• REM: Write-up fourth section of docs (#1680) [@amirebrahimi]
• upgrade _run to a public function (#1684) [@natestemen]
• Update pyquil requirement from ~=3.3.2 to ~=3.3.3 (#1686) [@dependabot[bot]]
• Update qiskit requirement from ~=0.39.5 to ~=0.40.0 (#1687) [@dependabot[bot]]
• Calibration improvements (#1676) [@natestemen]
• Further updates related to the measurement result class (#1673) [@andreamari]
• DDD on IBMQ backends (#1665) [@Misty-W]
• Update amazon-braket-sdk requirement from ~=1.35.2 to ~=1.35.3 (#1674) [@dependabot[bot]]
• Update qiskit requirement from ~=0.39.4 to ~=0.39.5 (#1675) [@dependabot[bot]]
• Use md extension for myst markdown files (#1671) [@natestemen]
• add H2 image (#1677) [@andreamari]
• Use source svg files instead of exported pngs (#1651) [@amirebrahimi]
• Improve and modify MeasurementResult class (#1670) [@andreamari]
• Update pennylane requirement from ~=0.27.0 to ~=0.28.0 (#1643) [@dependabot[bot]]
• Update cirq requirement from ~=1.0.0 to ~=1.1.0 (#1644) [@dependabot[bot]]
• loosen numpy requirements (#1672) [@natestemen]
• clean up latex (#1669) [@natestemen]
• Fix executor and update wording of DDD tutorial (#1655) [@Misty-W]
• Update scipy requirement from ~=1.9.3 to ~=1.10.0 (#1657) [@dependabot[bot]]
• update link (#1661) [@natestemen]
• Update amazon-braket-sdk requirement from ~=1.35.1 to ~=1.35.2 (#1656) [@dependabot[bot]]
• Update numpy requirement from ~=1.24.0 to ~=1.24.1 (#1652) [@dependabot[bot]]