Announcements

• Upgraded pyQuil to v4 (gh-237). As a result, the minimum supported Python version is now 3.8.

Announcements

• Upgraded pyQuil to v3 (gh-215). As a result, the minimum supported Python version is now 3.7.

Bugfixes

• Fix compiler timeout during test (@jlapeyre) (gh-208)
• Fix type error in pauli coefficient in observable calibration for recent pyquil versions (@kylegulshen) (gh-207)
• Add noise definition only once to quil program (@kylegulshen) (gh-206)

Breaking Changes

• Major module re-org of superoperator tools into operator_tools also moved random_operators to the operator tools module. Added type checking in random operators, added new module to check plain old operators are unitary etc (gh-150, 140, 164).
• Remove symmetrization functionality from observable_estimation in favor of pyquil functionality (gh-194).
• Methods in fitting renamed to be less ambiguous decay_constant_param_decay -> decay_time_param_decay and
  fit_decay_constant_param_decay -> fit_decay_time_param_decay. Correspondingly, the fit parameter was renamed
  decay_constant -> decay_time(gh-175)
• generate_cz_phase_ramsey_experiment was made plural, consistent with rest of qubit_spectroscopy (gh-175)
• acquire_cz_phase_ramsey_data removed in favor of estimate_observables and all other specific acquire_* methods
  in qubit_spectroscopy.py were removed in favor of acquire_qubit_spectroscopy_data (gh-175)
• argument order standardized, which changed the api of generate_exhaustive_process_dfe_experiment,
  generate_exhaustive_state_dfe_experiment, generate_monte_carlo_state_dfe_experiment,
  generate_monte_carlo_process_dfe_experiment, robust_phase_estimate,
  and positional arg name of acquire_dfe_data (gh-182)

Improvements and Changes

• Fixed the years in this Change log file 2018 -> 2019
• Added linear inversion process tomography (gh-142)
• Changed qubit tensor factor ordering of state tomography estimates to match that of process tomography, e.g.
  tomographizing the plus eigenstate of X0 * Z1 and passing in qubits = [0,1] will yield the state
  estimate corresponding to |+0> = (1, 0, 1, 0)/sqrt(2) rather than |0+> (gh-142)
• Improved the superoperator_tools notebook and the random_operators notebook (gh-98)
• Improvements to Ripple carry adder notebook, added tests for non parametric bit string
  prep program in utils (gh-98)
• Added the ability to project a Choi matrix to the closest unitary (gh-159, 157)
• Reduced local test run time from 11min to 5min (gh-160)
• Major changes and improvements to all notebooks (gh-148, 149, 153, 154, 155, 156, 165, 167, 172, 182(see 183))
• Speedup the tests (gh-158, 161)
• Complete overhaul/addition of documentation in docs folder (gh-170, 174)
• Github PR and bug report templates added (gh-177, 182)
• merge_disjoint_experiments and get_results_by_qubit_groups added to observable_estimation.py to facilitate
  running experiments 'in parallel' on a QPU and analyzing the results separately (gh-182)
• various do_* methods added that wrap various experiments into a single method with sensible defaults (gh-182)
• examples notebooks moved to docs/ directory to be rendered within documentation (gh-182)
• tqdm progress bars added to most data acquisition methods (gh-182)

Bugfixes

• Dagger is now implemented in pyquil as a gate-level modifier, but this doesn't play well with noise models on the QVM
  so a stop-gap was put into basic_compile to hand compile the dagger modifier (gh-169)
• Compiler sometimes failed to find connected subgraphs of qubits (gh-188)
• QPU cannot handle integer parameters (gh-188)

Breaking Changes

• operator_estimation.py is entirely replaced. All changes from (gh-135) except where stated otherwise.

• operator_estimation.py -> observable_estimation.py (gh-138)

• pyquil.operator_estimation dependencies replaced with forest.benchmarking.observable_estimation (gh-129,132,133,134,135)

• operator_estimation.TomographyExperiment.out_op -> observable_estimation.ObservablesExperiment.out_observable

• operator_estimation.measure_observables -> observable_estimation.estimate_observables

• operator_estimation.group_experiments -> observable_estimation.group_settings

• utils.all_pauli_terms -> utils.all_traceless_pauli_terms

• DFEData and DFEEstimate dataclasses removed in favor of ExperimentResult and tuple of results respectively (gh-134).

• plotting moved out of qubit_spectroscopy; instead, use fit_*_results() to get a lmfit.model.ModelResult and pass this into analysis.fitting.make_figure()

• pandas.DataFrame is no longer used in randomized_benchmarking (gh-133), qubit_spectroscopy (gh-129), and robust_phase_estimation (gh-135). These now make use of observable_estimation.ObservablesExperiment, and as such the API has changed substantially. Please refer to example notebooks for new usage.

• pandas.DataFrame methods removed from quantum_volume. See examples notebook for alternative usage (gh-136).

• utils.determine_simultaneous_grouping() removed in favor of similar functionality in observable_estimation.group_settings

• SIC state helpers removed from utils

• default utils.str_to_pauli_term now associates left-most character of input pauli_str with qubit 0. If qubit_labels are provided then the qubits label the characters in order.

• utils.all_pauli_*_terms -> utils.all_traceless_pauli_*_terms to reflect fact that identity term is not included.

• utils.pauli_basis_pauli_basis_measurements removed

Improvements and Changes

• analysis.fitting has been expanded to hold each fit model used in qubit_spectroscopy and randomized_benchmarking (gh-133, gh-129)

• RX(angle) for arbitrary angle now supported by basic_compile

• observable_estimation.estimate_observables (formerly pyquil.operator_estimation.measure_observables) has been decomposed into separate steps:

  • generate_experiment_programs(), which converts and experiment into a list of programs
  • optional symmetrization, which expands each program into a group of programs that accomplish symmetrization
  • data collection and optional consolidate_symmetrization_outputs() which collects data used for estimates
  • calibrate_observable_estimates() which can be used to update estimates after collecting calibration data

• plotting.state_process.plot_pauli_transfer_matrix() now automatically casts input to np.real_if_close (gh-132)

• _state_tomo_settings() no longer includes all-Identity term (gh-132).

Bugfixes

• t2 experiments now implement correct echo sequence (gh-129)

Improvements and Changes:

• Moved bitstring prep/measure program creation helpers to utils (gh-118)
• Added functoinality to plotting module: two ways to visualize a quantum state in the Pauli basis, plotting of a Pauli Transfer Matrix, plotting a real matrix using a Hinton diagram, the addition of the computational basis as a predefined basis object (gh-119)
• Refactor iterative MLE to use ExperimentResults directly (gh-120)
• Combined graph_state and bell_state modules into entangled_state module, added deprecation warnings for the old modules (gh-122)
• Made Ipython Notebooks a part of testing (gh-123)
• Resolve test warnings and doc string formatting issues (gh-124)
• Breaking change. Bump version and delete graph_state and bell_state modules (gh-125)
• Added the ability to check if the Kraus operators are valid (PR 128)

Improvements and Changes

• Updated requirements.txt and setup.py files (gh-83)
• Added support for chi superoperator conversion and augmented documentation for
  superoperator representations (gh-76)
• Renamed superoperator_conversion to superoperator_tools (gh-100) to reflect
  new functionality, including helpers to apply a Choi process to a state, compute
  the Pauli twirl (gh-101), testing properties (e.g. CP, TP) of channels in the Choi
  representation (gh-109), and projecting Choi matrices to nearby processes satisfying
  those properties (gh-114)
• Following update to pyQuil version 2.7.2, changed stddev to std_err and removed qubits
  argument when using pyquil TomographyExperiment (gh-107)
• Changed the default input basis from SIC to Pauli for process tomography (gh-105)
• Standardized around use of pyquil.gate_matrices for definitions of gate matrices (gh-103)
• Added support non-square Kraus operators to superoperator conversion tools (gh-102)
• Renamed diamond_norm to diamond_norm_distance gh-104
• Made use of superoperator tools wherever possible throughout the repo (gh-111)
• Standardized around use of dim as variable name for dimension (gh-112)
• Added entanglement_fidelity calculation in distance_measures.py (gh-116)

Bugfixes

• Fixed keyword argument name symmetrize_readout in call to pyQuil's
  measure_observables (gh-115)

Initial public release of forest-benchmarking.

The repository is now available on PyPI here.

See the v0.3 milestone for a complete list of all issues addressed and pull requests merged for this release.