Experimental demonstration of composite adiabatic passage

Abstract

We report an experimental demonstration of composite adiabatic passage (CAP) for robust and efficient manipulation of two-level systems. The technique represents a altered version of rapid adiabatic passage (RAP), driven by composite sequences of radiation pulses with appropriately chosen phases. We implement CAP with radio-frequency pulses to invert (i.e., to rephase) optically prepared spin coherences in a ${\text{Pr}}^{3+}\text{:}{\text{Y}}_{2}{\text{SiO}}_{5}$ crystal. We perform systematic investigations of the efficiency of CAP and compare the results with conventional $\ensuremath{\pi}$ pulses and RAP. The data clearly demonstrate the superior features of CAP with regard to robustness and efficiency, even under conditions of weakly fulfilled adiabaticity. The experimental demonstration of composite sequences to support adiabatic passage is of significant relevance whenever a high efficiency or robustness of coherent excitation processes need to be maintained, e.g., as required in quantum information technology.