- class VarQITE(ansatz, initial_parameters, variational_principle=None, estimator=None, ode_solver=<class 'qiskit_algorithms.time_evolvers.variational.solvers.ode.forward_euler_solver.ForwardEulerSolver'>, lse_solver=None, num_timesteps=None, imag_part_tol=1e-07, num_instability_tol=1e-07)#
Variational Quantum Imaginary Time Evolution algorithm.
ansatz (QuantumCircuit) – Ansatz to be used for variational time evolution.
variational_principle (ImaginaryVariationalPrinciple | None) – Variational Principle to be used. Defaults to
estimator (BaseEstimator | None) – An estimator primitive used for calculating expectation values of TimeEvolutionProblem.aux_operators.
ode_solver (Type[OdeSolver] | str) – ODE solver callable that implements a SciPy
OdeSolverinterface or a string indicating a valid method offered by SciPy.
lse_solver (Callable[[np.ndarray, np.ndarray], np.ndarray] | None) – Linear system of equations solver callable. It accepts
None, the default
np.linalg.lstsqsolver is used.
num_timesteps (int | None) – The number of timesteps to take. If
None, it is automatically selected to achieve a timestep of approximately 0.01. Only relevant in case of the
imag_part_tol (float) – Allowed value of an imaginary part that can be neglected if no imaginary part is expected.
num_instability_tol (float) – The amount of negative value that is allowed to be rounded up to 0 for quantities that are expected to be non-negative.
Apply Variational Quantum Time Evolution to the given operator.
evolution_problem (TimeEvolutionProblem) – Instance defining an evolution problem.
Result of the evolution which includes a quantum circuit with bound parameters as an evolved state and, if provided, observables evaluated on the evolved state.
ValueError – If
initial_stateis included in the
- Return type: