EstimatorQUIMB

class iqm.qaoa.backends.EstimatorQUIMB

Bases: EstimatorBackend

The estimator class for calculating the expectation value using the tensor network package quimb.

Methods

estimate(qaoa_object)

Calculates the expectation value of the Hamiltonian by contracting the RCC tensor networks in quimb.

estimate(qaoa_object)

Calculates the expectation value of the Hamiltonian by contracting the RCC tensor networks in quimb.

Uses quimb_tn() to build a Circuit. This object represents the QAOA circuit, so it can be used to calculate expectation values (using the function local_expectation()). The local expectation values are added to get the expectation value of the full Hamiltonian. The calculation includes a constant term (coming from the translation of a QUBO problem to a Hamiltonian).

Parameters:

qaoa_object (QUBOQAOA) – The instance of QUBOQAOA whose expectation value is to be calculated.

Returns:

The expectation value of the energy of the QAOA state using angles.

Return type:

float