Quantum state preparation is vital to quantum computation and quantum
information processing tasks. In adiabatic state preparation, the target state
is theoretically obtained with nearly perfect fidelity if the control parameter
is tuned slowly enough. As this, however, leads to slow dynamics, it is often
desirable to be able to do processes faster. In this work, we employ two global
optimization methods to estimate the quantum speed limit for few-fermion
systems confined in a one-dimensional harmonic trap. Such systems can be
produced experimentally in a well controlled manner. We determine the optimized
control fields and achieve a reduction in the ramping time of more than a
factor of four compared to linear ramping. We also investigate how robust the
fidelity is to small variations of the control fields away from the optimized
shapes.Comment: 8 pages, 5 figures, 1 tabl
