BitStrings

class pulser.backend.BitStrings(*, evaluation_times=None, num_shots=1000, one_state=None, tag_suffix=None)

Bases: Observable

Stores bitstrings sampled from the state at the evaluation times.

Error rates are taken from the NoiseModel passed to the backend via the EmulationConfig. The bitstrings are stored as a Counter[str].

Parameters:

• evaluation_times (Sequence[float] | None, default: None) – The relative times at which to sample bitstrings. If left as None, uses the default_evaluation_times of the backend’s EmulationConfig.

• num_shots (int, default: 1000) – How many bitstrings to sample each time this observable is computed.

• one_state (Literal['u', 'd', 'r', 'g', 'h', 'x'] | Literal['0', '1'] | None, default: None) – The eigenstate that measures to 1. Can be left undefined if the state’s eigenstates form a known eigenbasis with a defined “one state”.

• tag_suffix (str | None, default: None) – An optional suffix to append to the tag. Needed if multiple instances of the same observable are given to the same EmulationConfig.

Attributes

default_aggregation_method
tag	Label for the observable, used to index the Results object.
uuid	A universal unique identifier for this instance.

Methods

apply

Calculates the observable to store in the Results.

Signatures

apply(*, config, state, **kwargs)

Calculates the observable to store in the Results.

Return type:

Counter[str]

property tag: str

Label for the observable, used to index the Results object.

Within a Results instance, all computed observables must have different tags.

Returns:

The tag of the observable.

property uuid: UUID

A universal unique identifier for this instance.