Optical Feshbach resonances through a molecular dark state: Efficient manipulation of $p$-wave resonances in fermionic $^{171}$Yb atoms

摘要

In a recent experiment by Yamazaki {\it et al.} [Phys.Rev. A {\bf 87} 010704(R) (2013) ], $p$-wave optical Feshbach resonance in fermionic $^{171}$Yb atomsusing purely long-range molecular excited states has been demonstrated. Wetheoretically show that, if two purely long range excited states of $^{171}$Ybare coupled to the ground-state continuum of scattering states with two lasers,then it is possible to significantly suppress photoassociative atom loss by adark resonance in the excited states. We present a general theoreticalframework for creating a dark state in electronically excited molecularpotential for the purpose of increasing the efficiency of an optical Feshbachresonance. This can be accomplished by properly adjusting the relativeintensity, phase, polarizations and frequency detunings of two lasers. Wepresent selective numerical results on atom loss spectra, $p$-wave elastic andinelastic scattering cross sections of $^{171}$Yb atoms to illustrate theeffects of the molecular dark state on optical Feshbach resonance.