High-fidelity formation of deeply bound ultracold molecules via non-Hermitian shortcut to adiabaticity

Stimulated Raman adiabatic passage allows robust transfer between two ends of a three-state quantum system and has been employed to transfer weakly bound Feshbach molecules into their deeply bound rovibrational ground state. However, the efficient transfer remains to be explored. Here we propose a possible alternative route, based on a recently developed non-Hermitian shortcut to adiabaticity method. It is able to realize single-step transfer efficiencies up to 100% even in the presence of a decaying excited level, surpassing all the previous methods. We also prove that our scheme is robust against the external field parameter fluctuations and is expected to be applicable for abundant molecular species.