algorithm

The perceval.algorithm package contains the code of several simple and generic quantum algorithms. It provides a Computer and Experiment-centric syntax to run an algorithm locally or remotely, on a simulator or an actual QPU.

All algorithms take either a local or a remote computer as parameter, in order to perform a task based on a given Experiment.

>>> from perceval import SimulatedComputer, BasicState, Experiment
>>> from perceval.algorithm import Analyzer
>>> experiment = pcvl.Experiment(pcvl.BS())  # No need to declare the input state here
>>> computer = pcvl.SimulatedComputer("CliffordClifford2017")
>>> with computer.acquire():
...     ca = pcvl.algorithm.Analyzer(computer, experiment, [BasicState([1, 1])], "*")
...     ca.compute()

Note

Algorithms may create one or several Execution internally, that are run sequentially.

Samples of interest vs Shots

On a QPU, the acquisition is measured in shots. A shot is any coincidence with at least 1 detected photon. Shots act as credits on the Cloud services. Users have to set a maximum shots value they are willing to use for any algorithm. Note that this is a per-Execution limit (so globally, an algorithm may use more than this number of shots).

>>> import perceval as pcvl
>>> remote_c = pcvl.RemoteComputer(pcvl.QuandelaCommunicationLayer("sim:sampling"))
>>> experiment = Experiment(pcvl.BS())
>>> with remote_c.acquire():
...     analyzer = pcvl.algorithm.Analyzer(remote_c, experiment, [BasicState([1, 1])], "*", max_shots_per_call=500_000)
...     analyzer.compute()

Here, the computation runs on the sim:sampling platform.

For more information about the shots and shots/samples ratio estimate, please read Remote computing tutorial.