qrunch.quantum.estimators.memory_restricted_estimator

Module containing the a memory restricted estimator.

Classes

MemoryRestrictedEstimator

Class for estimating observables using the memory restricted estimator.

class MemoryRestrictedEstimator

Bases: Estimator

Class for estimating observables using the memory restricted estimator.

__init__(options: MemoryRestrictedSimulatorOptions | None = None, grouper: MeasurementGrouper | None = None, error_mitigator: EstimatorErrorMitigator | None = None, measurement_cache: MeasurementCache | None = None) → None

Initiate an instance of the MemoryRestrictedEstimator.

Parameters:

• options (MemoryRestrictedSimulatorOptions | None) – Options to be used in the MemoryRestrictedEstimator.

• grouper (MeasurementGrouper | None) – Grouper to be used for grouping the observables into measurable partitions.

• error_mitigator (EstimatorErrorMitigator | None) – Error mitigator to be used for encoding the observable or circuit more error resistantly.

• measurement_cache (MeasurementCache | None) – Cache to use for storing and reusing measurements.

Return type:

None

clear_cache() → None

Clear the measurement cache.

Return type:

None

has_spin_particle_conservation() → bool

Return True, if the estimator is set to use spin particle conservation.

Return type:

bool

has_total_particle_conservation() → bool

Return True, if the estimator is set to use total particle conservation.

Return type:

bool

run(observables: Sequence[int | float | complex | Expression[PauliOperators]] | int | float | complex | Expression[PauliOperators] | Sequence[HermitianPauliSum] | HermitianPauliSum, circuits: Circuit | Sequence[Circuit], shots: int | ShotsPerGroup | None) → ExpectationValue | list[ExpectationValue] | EstimatorResults

Estimate the value of the observables using the circuit state.

For each observable the following will be calculated: <circuit|observable|circuit>.

Parameters:

• observables (Sequence[int | float | complex | Expression[PauliOperators]] | int | float | complex | Expression[PauliOperators] | Sequence[HermitianPauliSum] | HermitianPauliSum) – Observable(s) to be estimated.

• circuits (Circuit | Sequence[Circuit]) – States to make estimation from.

• shots (int | ShotsPerGroup | None) – number of shots or None if using a full state vector calculation.

Return type:

ExpectationValue | list[ExpectationValue] | EstimatorResults

validate_shots_type(shots_type: Type[int | ShotsPerGroup | None]) → list[str]

Validate that the sampler supports the given shots type. Return a list of error messages if not supported.

Parameters:

shots_type (Type[int | ShotsPerGroup | None])

Return type:

list[str]