TimeEvolutionProblem
class TimeEvolutionProblem(hamiltonian, time, initial_state=None, aux_operators=None, truncation_threshold=1e-12, t_param=None, param_value_map=None)
Bases: object
Time evolution problem class.
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.
hamiltonian
initial_state
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.
Type
QuantumCircuit | Statevector | None
aux_operators
Optional list of auxiliary operators to be evaluated with the evolved initial_state and their expectation values returned.
Type
ListOrDict[BaseOperator | PauliSumOp] | None
truncation_threshold
Defines a threshold under which values can be assumed to be 0. Used when aux_operators is provided.
Type
float
t_param
Time parameter in case of a time-dependent Hamiltonian. This free parameter must be within the hamiltonian.
Type
Parameter | None
param_value_map
Maps free parameters in the problem to values. Depending on the algorithm, it might refer to e.g. a Hamiltonian or an initial state.
Type
dict[Parameter, complex] | None
Parameters
- hamiltonian (BaseOperator | PauliSumOp) – The Hamiltonian under which to evolve the system.
- time (float) – Total time of evolution.
- initial_state (QuantumCircuit |Statevector | 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 (ListOrDict[BaseOperator | PauliSumOp] | None) – Optional list of auxiliary operators to be evaluated with the evolved
initial_stateand their expectation values returned. - truncation_threshold (float) – Defines a threshold under which values can be assumed to be 0. Used when
aux_operatorsis provided. - t_param (Parameter | None) – Time parameter in case of a time-dependent Hamiltonian. This free parameter must be within the
hamiltonian. - param_value_map (Mapping[Parameter, complex] | None) – 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
TimeEvolutionProblem.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