seemps.optimization.gradient_descent#

seemps.optimization.gradient_descent(H: MPO | MPOList | MPOSum, guess: MPS | MPSSum, maxiter: int = 1000, tol: float = 1e-13, tol_up: float | None = None, tol_variance: float = 1e-14, strategy: Strategy = DESCENT_STRATEGY, callback: Callable[[MPS, OptimizeResults], Any] | None = None) OptimizeResults[source]#

Ground state search of Hamiltonian H by gradient descent.

Parameters:
HMPO | MPOList | MPOSum

Hamiltonian in MPO form.

stateMPS | MPSSum

Initial guess of the ground state.

maxiterint

Maximum number of iterations (defaults to 1000).

tolfloat

Energy variation that indicates termination (defaults to 1e-13).

tol_upfloat, default = tol

If energy fluctuates up below this tolerance, continue the optimization.

tol_variancefloat

Energy variance target (defaults to 1e-14).

strategyStrategy, default = DESCENT_STRATEGY

Linear combination of MPS truncation strategy.

callbackCallable[[MPS, OptimizeResults], Any] | None

A callable called after each iteration (defaults to None).

Returns:
OptimizeResults

Results from the optimization. See OptimizeResults.