Functionalizing aromatic compounds with optical cycling centres

Pathway toward Optical Cycling and Laser Cooling of Functionalized Arenes

“…We also note that in every case, the excited molecules in the state can decay to the lower energy state via collisional relaxation. This process has been observed in similar experiments. ,, If a significant fraction of the molecules in the state decay via collisional relaxation, we expect to see not only the decay but also the higher vibrational decay peaks. Such collisional relaxation peaks are denoted with * in Figure c­(i–iii).…”

“…However, our calculations predict a significant bending contribution for CaO1Nap for both the first and second harmonics (Figure ). The contribution of the bending mode for CaO1Nap is by far the highest among all species examined here and the CaO--X molecules examined in ref . This is likely related to the fact that the CaO group in CaO1Nap is bonded to the carbon at position 1 of naphthalene (Figure a­(ii)).…”

“…Theory, however, fails to predict significant decay to the bending mode of the M–O-C bond for MO2Nap. We speculate that this discrepancy is due to vibronic couplings among and anharmonicities within the low-frequency modes, ,,, which are beyond the scope of the calculations presented in this work. However, our calculations predict a significant bending contribution for CaO1Nap for both the first and second harmonics (Figure ).…”

“…Further, the theoretical calculations suggested that increasing the electron-withdrawing strength of the ligand by substitutions in the ligand could improve optical cycling performance. Some of these concepts were recently demonstrated for ligands composed of phenyl and its derivatives, where it was suggested that the alkaline earth oxide unit could be considered a quantum functional group that could be used to gain control of larger molecules and provide a generic qubit moiety for attaching to large molecules and perhaps surfaces.…”

Optical trapping of a polyatomic molecule

“…At increased molecule number densities, studies of collisions [34], ultracold chemistry [32,33], or bulk dipolar gases [64,65] should be possible. Finally, this work suggests that optical trapping may be viable for several large classes of polyatomic molecules for which optical cycling is expected to be possible [66], ranging from MOR type molecules [67] (of which several have already been laser cooled in one dimension [68][69][70]) to asymmetric molecules [71], and possibly more complex species [72][73][74][75]. Several of these species (e.g., CaSH and CaOCH 3 ) have closely-spaced parity doublet states that are expected to have even longer radiative lifetimes (>10 s) than the X 2 Σ + (010) state in CaOH.…”