Enhanced Ramsey interferometry via stimulated Raman adiabatic passage

Ramsey interferometry, a cornerstone technique in quantum sensing, achieves high sensitivity by enabling precise control and measurement of quantum states through extended coherence times. In three-level systems, the double-quantum (DQ) Ramsey scheme faces challenges in maintaining coherence and robustness against practical imperfections, such as variations in pulse amplitude and detuning. We present a Ramsey technique which addresses these limitations, employing a modified Stimulated Raman Adiabatic Passage (STIRAP). This method replaces the traditional π/2 pulses with Half-STIRAP (H-STIRAP) pulses, enabling the adiabatic generation of quantum superpositions with maximal coherence. The new scheme effectively suppresses single-quantum transitions and ensures high Ramsey fringe contrast even under realistic imperfections, such as single-photon detuning and pulse-area fluctuations. The scheme's enhanced performance over conventional methods is confirmed by both theory and experiment. The robustness of this method opens new avenues for novel quantum sensing applications, particularly in magnetometry and inertial navigation, where precision and reliability are crucial.