  We study experimentally and theoretically the transfer of population between
the ground state and the second excited state in a transmon circuit by the use
of superadiabatic stimulated Raman adiabatic passage (saSTIRAP). We show that
the transfer is remarkably resilient against variations in the amplitudes of
the pulses (scaling errors), thus demostrating that the superadiabatic process
inherits certain robustness features from the adiabatic one. In particular, we
put in evidence a new plateau that appears at high values of the
counterdiabatic pulse strength, which goes beyond the usual framework of
saSTIRAP.
