Module: openfermion.measurements

Modules

equality_constraint_projection module: Module to reduce operator variance using equality RDM constraints.

fermion_partitioning module

qubit_partitioning module: Code to generate Pauli strings for measurement of local operators

rdm_equality_constraints module: Constraints on fermionic reduced density matrices

vpe_estimators module: Classes to assist in processing of VPE (ArXiv:2010.02538) signal data

Classes

class PhaseFitEstimator: A VPE estimator that works by fitting a set of known frequencies.

Functions

apply_constraints(...): Function to use linear programming to apply constraints.

binary_partition_iterator(...): Generator for a list of 2-partitions of N qubits

constraint_matrix(...): Function to generate matrix of constraints.

get_interaction_rdm(...): Build an InteractionRDM from measured qubit operators.

get_phase_function(...): Generates an estimate of the phase function g(t) from circuit output

group_into_tensor_product_basis_sets(...): Split an operator (instance of QubitOperator) into sub-operator

linearize_term(...): Function to return integer index of term indices.

one_body_fermion_constraints(...): Generates one-body positivity constraints on fermionic RDMs.

operator_to_vector(...): Function to map operator to vector.

pair_between(...): Pairs between two fragments of a larger list

pair_within(...): Generates pairings of labels that contain each pair at least once.

pair_within_simultaneously(...): Generates simultaneous pairings between four-element combinations

pair_within_simultaneously_binned(...): Generates symmetry-respecting pairings between four-elements in a list

pair_within_simultaneously_symmetric(...): Generates symmetry-respecting pairings between four-elements in a list

partition_iterator(...): Generator for a list of k-partitions of N qubits such that

pauli_string_iterator(...): Generates a set of Pauli strings such that each word

two_body_fermion_constraints(...): Generates two-body positivity constraints on fermionic RDMs.

unlinearize_term(...): Function to return integer index of term indices.

vector_to_operator(...): Function to map vector to operator.