xeb_fidelity: Xeb fidelity

Description Usage Arguments Details Value Raises

View source: R/sampling_simulations.R

Description

Estimates XEB fidelity from one circuit using user-supplied estimator.

Usage

1
xeb_fidelity(circuit, bitstrings, qubit_order, amplitudes = NULL, estimator)

Arguments

circuit

Random quantum circuit which has been executed on quantum processor under test.

bitstrings

Results of terminal all-qubit measurements performed after each circuit execution as integer array where each integer is formed from measured qubit values according to 'qubit_order' from most to least significant qubit, i.e. in the order consistent with 'cirq.final_wavefunction'.

qubit_order

Qubit order used to construct bitstrings enumerating qubits starting with the most sigificant qubit.

amplitudes

Optional mapping from bitstring to output amplitude. If provided, simulation is skipped. Useful for large circuits when an offline simulation had already been peformed.

estimator

Fidelity estimator to use, see above. Defaults to the linear XEB fidelity estimator. Returns: Estimate of fidelity associated with an experimental realization of circuit which yielded measurements in bitstrings. Raises:

Details

Fidelity quantifies the similarity of two quantum states. Here, we estimate the fidelity between the theoretically predicted output state of circuit and the state producted in its experimental realization. Note that we don't know the latter state. Nevertheless, we can estimate the fidelity between the two states from the knowledge of the bitstrings observed in the experiment. In order to make the estimate more robust one should average the estimates over many random circuits. The API supports per-circuit fidelity estimation to enable users to examine the properties of estimate distribution over many circuits. See https://arxiv.org/abs/1608.00263 for more details.

Value

Estimate of fidelity associated with an experimental realization of circuit which yielded measurements in bitstrings. Raises: ValueError: Circuit is inconsistent with qubit order or one of the bitstrings is inconsistent with the number of qubits.

Raises

ValueError: Circuit is inconsistent with qubit order or one of the bitstrings is inconsistent with the number of qubits.


henry090/Cirq documentation built on June 13, 2020, 1:28 a.m.