Deterministic facilitated excitation of the weakly driven atom in heteronuclear Rydberg atom pairs beyond antiblockade

Due to the intrinsic strong blockaded interaction shifting the energy level of the Rydberg state, the steady Rydberg probability may be substantially restrained to a low level, especially for atoms suffering from weak driving. We report an exotic excitation facilitation using strong blockaded energy shifting the double excitation state, leading to the weakly driven atom deterministically excited by a significantly improved fraction even at far off-resonant regimes. This phenomenon is attributed to the effective induction of a reduced detuning to the weakly driven atom by optimizing parameters of an auxiliary strongly driven atom, arising from a modified large probability preserved for a broadening range of detuning. The influence from breaking the blockade condition on the excitation probability is also discussed. In contrast to previous approaches, our excitation facilitation mechanism does not rely on the antiblockade effect to the compensation of Rydberg energy, serving as a fresh way to a deterministic single-atom excitation of the target atom in a pair of heteronuclear Rydberg atoms, where a strong interatomic interaction is required.