Revert "Implemented general Quantum Time Evolution Framework interfaces. (#7669)"

qiskit/algorithms/__init__.py

@@ -93,22 +93,6 @@
    NumPyEigensolver
 
 
-Evolvers
---------
-
-Algorithms to evolve quantum states in time. Both real and imaginary time evolution is possible
-with algorithms that support them. For machine learning, Quantum Imaginary Time Evolution might be
-used to train Quantum Boltzmann Machine Neural Networks for example.
-
-.. autosummary::
-   :toctree: ../stubs/
-   :nosignatures:
-
-    RealEvolver
-    ImaginaryEvolver
-    EvolutionResult
-    EvolutionProblem
-
 Factorizers
 -----------
 
@@ -204,9 +188,6 @@
 """
 
 from .algorithm_result import AlgorithmResult
-from .evolvers import EvolutionResult, EvolutionProblem
-from .evolvers.real.real_evolver import RealEvolver
-from .evolvers.imaginary.imaginary_evolver import ImaginaryEvolver
 from .variational_algorithm import VariationalAlgorithm, VariationalResult
 from .amplitude_amplifiers import Grover, GroverResult, AmplificationProblem, AmplitudeAmplifier
 from .amplitude_estimators import (
@@ -264,10 +245,6 @@
     "MaximumLikelihoodAmplitudeEstimationResult",
     "EstimationProblem",
     "NumPyEigensolver",
-    "RealEvolver",
-    "ImaginaryEvolver",
-    "EvolutionResult",
-    "EvolutionProblem",
     "LinearSolverResult",
     "Eigensolver",
     "EigensolverResult",

qiskit/algorithms/eigen_solvers/eigen_solver.py

@@ -13,13 +13,15 @@
 """The Eigensolver interface"""
 
 from abc import ABC, abstractmethod
-from typing import Optional, List, Tuple
+from typing import Dict, Optional, List, Union, Tuple, TypeVar
 
 import numpy as np
-
 from qiskit.opflow import OperatorBase
 from ..algorithm_result import AlgorithmResult
-from ..list_or_dict import ListOrDict
+
+# Introduced new type to maintain readability.
+_T = TypeVar("_T")  # Pylint does not allow single character class names.
+ListOrDict = Union[List[Optional[_T]], Dict[str, _T]]
 
 
 class Eigensolver(ABC):

qiskit/algorithms/eigen_solvers/numpy_eigen_solver.py

@@ -21,8 +21,7 @@
 from qiskit.opflow import I, ListOp, OperatorBase, StateFn
 from qiskit.utils.validation import validate_min
 from ..exceptions import AlgorithmError
-from .eigen_solver import Eigensolver, EigensolverResult
-from ..list_or_dict import ListOrDict
+from .eigen_solver import Eigensolver, EigensolverResult, ListOrDict
 
 logger = logging.getLogger(__name__)
 

qiskit/algorithms/minimum_eigen_solvers/minimum_eigen_solver.py

@@ -13,13 +13,15 @@
 """The Minimum Eigensolver interface"""
 
 from abc import ABC, abstractmethod
-from typing import Optional, Tuple
+from typing import Dict, Optional, List, Union, Tuple, TypeVar
 
 import numpy as np
-
 from qiskit.opflow import OperatorBase
 from ..algorithm_result import AlgorithmResult
-from ..list_or_dict import ListOrDict
+
+# Introduced new type to maintain readability.
+_T = TypeVar("_T")  # Pylint does not allow single character class names.
+ListOrDict = Union[List[Optional[_T]], Dict[str, _T]]
 
 
 class MinimumEigensolver(ABC):

qiskit/algorithms/minimum_eigen_solvers/numpy_minimum_eigen_solver.py

@@ -18,8 +18,7 @@
 
 from qiskit.opflow import OperatorBase
 from ..eigen_solvers.numpy_eigen_solver import NumPyEigensolver
-from .minimum_eigen_solver import MinimumEigensolver, MinimumEigensolverResult
-from ..list_or_dict import ListOrDict
+from .minimum_eigen_solver import MinimumEigensolver, MinimumEigensolverResult, ListOrDict
 
 logger = logging.getLogger(__name__)
 

qiskit/algorithms/minimum_eigen_solvers/vqe.py

@@ -40,10 +40,9 @@
 from qiskit.utils.validation import validate_min
 from qiskit.utils.backend_utils import is_aer_provider
 from qiskit.utils import QuantumInstance, algorithm_globals
-from ..list_or_dict import ListOrDict
 from ..optimizers import Optimizer, SLSQP, OptimizerResult
 from ..variational_algorithm import VariationalAlgorithm, VariationalResult
-from .minimum_eigen_solver import MinimumEigensolver, MinimumEigensolverResult
+from .minimum_eigen_solver import MinimumEigensolver, MinimumEigensolverResult, ListOrDict
 from ..exceptions import AlgorithmError
 from ..aux_ops_evaluator import eval_observables