EvolutionProblem
class EvolutionProblem(hamiltonian, time, initial_state=None, aux_operators=None, truncation_threshold=1e-12, t_param=None, param_value_dict=None)
Bases: object
Pending deprecation: Evolution problem class.
The EvolutionProblem class has been superseded by the qiskit.algorithms.time_evolvers.TimeEvolutionProblem
class. This class will be deprecated in a future release and subsequently removed after that.
This class is the input to time evolution algorithms and must contain information on the total evolution time, a quantum state to be evolved and under which Hamiltonian the state is evolved.
Parameters
- hamiltonian (
OperatorBase
) – The Hamiltonian under which to evolve the system. - time (
float
) – Total time of evolution. - initial_state (
Union
[StateFn
,QuantumCircuit
,None
]) – The quantum state to be evolved for methods like Trotterization. For variational time evolutions, where the evolution happens in an ansatz, this argument is not required. - aux_operators (
Union
[List
[Optional
[OperatorBase
]],Dict
[str
,OperatorBase
],None
]) – Optional list of auxiliary operators to be evaluated with the evolvedinitial_state
and their expectation values returned. - truncation_threshold (
float
) – Defines a threshold under which values can be assumed to be 0. Used whenaux_operators
is provided. - t_param (
Optional
[Parameter
]) – Time parameter in case of a time-dependent Hamiltonian. This free parameter must be within thehamiltonian
. - param_value_dict (
Optional
[Dict
[Parameter
,complex
]]) – Maps free parameters in the problem to values. Depending on the algorithm, it might refer to e.g. a Hamiltonian or an initial state.
Raises
ValueError – If non-positive time of evolution is provided.
Methods
validate_params
EvolutionProblem.validate_params()
Checks if all parameters present in the Hamiltonian are also present in the dictionary that maps them to values.
Raises
ValueError – If Hamiltonian parameters cannot be bound with data provided.
Return type
None
Attributes
time
Returns time.
Return type
float