RandomMeasurement¶

class qumeas.random_measurement.RandomShadow(mole: Any | None = None, PauliObj: PauliContainer | None = None, state_prep: StatePreparation | None = None, basis: List[List[int]] | None = None)¶

Bases: object

Class for estimating expectation values of Pauli strings using classical shadow tomography (randomized measurement basis).

PauliObj¶

PauliContainer object holding Pauli strings, coefficients, state vector, and number of qubits.

Type:: PauliContainer

basis¶

Basis for measurements in classical shadow tomography.

Type:: Optional[List[List[int]]]

state_prep¶

State preparation object, can be an instance of StatePreparation or qiskitStatePreparation.

Type:: Optional[StatePreparation]

outbits¶

Measurement output bits. Contains list of measurement basis and another list of the corresponding classical bits. In the measurement basis, X,Y,Z are represented as integers 1,2,3 respectively.

Type:: Optional[List[List[List[int]]]]

compute_expectation(measure_basis, measure_outcome_bits)¶

Compute the expectation value from measurement bits.

Parameters:

measure_basis (List[Union[str, List[int]]]) – Measurement basis. Either list of Pauli operators (strings) or list of list of int representing Paulis, with 1 = ‘X’, 2 = ‘Y’, and 3 = ‘Z’.
measure_outcome_bits (List[Union[str, List[int]]]) – Measurement outcome (classical bits). Either a list of string or list of list of int. Binary bits can be passed in as string (e.g. [‘0011’, ‘0010’]. Also, supports a list, e.g. [[0, 0, 1, 1], [0, 0, 1, 0]] or in this format: [[1, 1, -1, -1],[1, 1, -1, 1]].

Returns:

Total expectation value.

Return type:

float

get_basis(M: int, seed: int | None = None)¶

Generate a random basis for measurements.

Parameters:

M (int) – Number of random basis to generate.
seed (Optional[int], default=None) – Random seed for reproducibility.

measure(shots: int = 1, M: int = 100, seed: int | None = None, nproc: int | None = 1)¶

Perform measurements using the state preparation object (state_prep).

Parameters:

shots (int, default=1) – Number of measurement shots. Currently, only supports for one shot measurements.
M (int, default=100) – Number of random basis in classical shadow tomography
seed (Optional[int], default=None) – Random seed for reproducibility.
nproc (Optional[int], default=1) – Number of processes for parallelization accross measurement bases. Each measurement basis can be processed in parallel across multiple processes, with each measurement further parallelized using OpenMP for optimal performance.

Returns:

Computed expectation value.

Return type:

float