Source code for qiskit_nature.second_q.problems.lattice_model_problem

# This code is part of a Qiskit project.
# (C) Copyright IBM 2022, 2023.
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

"""The Lattice Model Problem class."""

from __future__ import annotations

from typing import cast, Union

from qiskit_algorithms import EigensolverResult, MinimumEigensolverResult
from qiskit_nature.second_q.hamiltonians import LatticeModel
from import Interpretable

from .base_problem import BaseProblem
from .lattice_model_result import LatticeModelResult
from .lattice_properties_container import LatticePropertiesContainer
from .eigenstate_result import EigenstateResult

[docs]class LatticeModelProblem(BaseProblem): """A lattice model problem. This class specifically deals with handling of :class:`.LatticeModel` type hamiltonians. The following attributes can be read and updated once the ``LatticeModelProblem`` object has been constructed. Attributes: properties (LatticePropertiesContainer): a container for additional observable operator factories. """ def __init__(self, hamiltonian: LatticeModel) -> None: """ Args: hamiltonian: A lattice model class to create second quantized operators. Raises: TypeError: if the provided ``hamiltonian`` is not of type :class:`.LatticeModel`. """ super().__init__(hamiltonian) LatticePropertiesContainer = LatticePropertiesContainer() @property def hamiltonian(self) -> LatticeModel: """Returns the hamiltonian wrapped by this problem.""" return cast(LatticeModel, self._hamiltonian)
[docs] def interpret( self, raw_result: Union[EigenstateResult, EigensolverResult, MinimumEigensolverResult], ) -> LatticeModelResult: """Interprets a raw result in the context of this transformation. Args: raw_result: a raw result to be interpreted Returns: A lattice model result. """ eigenstate_result = super().interpret(raw_result) result = LatticeModelResult() result.combine(eigenstate_result) if isinstance(self.hamiltonian, Interpretable): self.hamiltonian.interpret(result) for prop in if isinstance(prop, Interpretable): prop.interpret(result) result.computed_lattice_energies = eigenstate_result.eigenvalues return result