Direct photoassociative formation of ultracold KRb molecules in the lowest vibrational levels of the electronic ground state

Abstract

We report continuous direct photoassociative formation of ultracold KRb molecules in the lowest vibrational levels (v ′′ = 0 − 10) of the electronic ground state (X 1 Σ + ), starting from 39 K and 85 Rb atoms in a magneto-optical trap. The process exploits a newfound resonant coupling between the 2(1), v ′ = 165 and 4(1), v ′ = 61 levels, which exhibit an almost equal admixture of the uncoupled eigenstates. The production rate of the X 1 Σ + (v ′′ =0) level is estimated to be 5 × 10 3 molecules/sec.

Spectroscopy and applications of the 3 3Σ+ electronic state of 39K85Rb

“…It is also noteworthy that the FCF for the transition to a(0,0) via the 2 3 , v = 6 level is two orders of magnitude higher than for 3 3 + , v = 13. Also, due to an appreciable tunneling width of the v = 13 level of the 3 3 + state the radiative decay probability might be compromised.…”

“…If we instead use the approximate case (a) potentials of Ref. 16, the FCF is still strongest for 2 3 , v = 6 → a(0,0) (where = 0 + , 0 − , and 1) except for the 2 3 2 state, for which v = 7 is the largest.…”

“…[1][2][3] Here we explore the possibility of using radiative transitions from the 3 3 + state to the X(0,0) rovibrational level in KRb. The transition is schematically represented in Figure 11.…”

“…[1][2][3][4][5][6][7][8] This has generated a renewed interest in the spectroscopy of these molecules, both heteronuclear and homonuclear, since accurate knowledge of the structure of the molecules provides the map required for their control. Various high-resolution spectroscopic techniques have thus evolved to provide the needed experimental information.…”

Photoionization spectrum of 85RbCs molecules produced by short range photoassociation

“…Another elegant but much more complex coherent control techniques, two-photon stimulated Raman adiabatic passage (STIRAP) process, recently has been used to produce the rovibrational ground state 87 RbCs molecules starting from Feshbach resonance molecules [22,20]. Especially, short range photoassociated RbCs molecules in ð2Þ 3 Π 0 7 excited state attract many researchers' attention for its simplify and continuous formation scheme to singlet Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jqsrt ground state molecules directly from ultracold atoms [23][24][25][26][27][28], just like the cases of LiCs [29], NaCs [30], KRb [31]. It needs to be declared that ð2Þ 3 Π 0 7 state is a co-written label of ð2Þ 3 Π 0 þ and ð2Þ 3 Π 0 À states.…”