Perceval Files

This update offers a whole new error mitigation feature, which needed a complete rewriting of the high-level classes of perceval (everything above Processor or RemoteProcessor). This new path also offers a lot of features that the old path couldn't do. The choice has been made to add a new main path for launching computations, while keeping the existing path as it is. The old path should not be used in new code anymore. You will find in the legacy page of the doc a table describing how to update the old workflow to the new one (link at the bottom of this text).

New features

• Error Mitigation classes:
• Can be inserted into a Computer for automatic use.
• Mitigates the probabilistic results got when using a QPU.
• Available algorithms:
  • Detector loss balancing
  • HOM/g2 mitigation
  • Loss mitigation
  • Compilation averaging
• Available as individual classes or through the ErrorMitigationFactory class.
• A new computation workflow:
• SimulatedComputer, RemoteComputer replace the Processor and RemoteProcessor, minus the Experiment, so they can easily be reused. The noise is linked to these Computers
• Computation handles all the computer-independant parameters (the Experiment, the number of shots/samples...).
• ComputationIterator also handles the iterations that were previously handled directly within the Sampler.
• Execution replaces both the LocalJob and RemoteJob.
• ExecutionGroup replaces the JobGroup. It is stored in the current folder, and can take both local and remote Execution, from any provider (Quandela, Scaleway, Kipu...).
• ExecutionFactory replaces the Sampler, and can create Executions and Computations easily.
• A CommunicationLayer for each provider replaces the Session, and must be inserted directly within the RemoteComputer. Computers give direct access to the start(), stop() and delete() methods, or as a context manager through the acquire() method.
• A new serialization framework
• This framework can handle most of the new classes
• It allows you to add any class to the known classes
• It handles repeated objects correctly

Improvements

• Algorithms (Analyzer, Tomography) now take an Experiment and a Computer, and can be executed with any kind of Computer.
• One RemoteConfig class per provider has been added, and the existing RemoteConfig class is used exclusively for Quandela.
• SimulatedComputers, and most Quandela platforms can now compute probs with a given number of samples.

Bug fixes

• BSCount to BSSamples conversion now gives the exact same amount of each state in a random order instead of a random sampling.
• Wrong polarized state size is detected sooner.
• Phase noise is now correctly applied to all layers of an Experiment, including inside feed-forward blocks.

Breaking changes

• While the global workflow of perceval has changed, any previous code should still work.
• Noise should no longer be set into Experiments, but into Computers instead.

A detailed documentation on how to update your Perceval code to version 1.3 is available here: https://perceval.quandela.net/docs/v1.3/legacy.html

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