Nona Semana Integrada do Instituto de Física de São Carlos

Depletion spectroscopy of ultracold νx=0 85Rb2 molecules trapped in a crossed optical dipole trap

Não agendado

20m

Doutorado

Palestrante

Henry Passagem (USP)

Descrição

In this work, we have loaded νx=0 85Rb2 ultracold molecules into a crossed optical dipole trap from a standard magneto optical trap using a single light beam. Such beam is composed of a single frequency coherent light source, which is responsible for short range PA of cold rubidium atoms, and an incoherent broadband light source which transfers the molecules in different vibrational levels (νx) of the singlet-ground-state X, into νx=0, through optical pumping. The molecules were observed, by REMPI technique, through 11 transitions from the νx=0 X1Σ+g ground state to the 21Σ+u excited state in the 20853-20985~cm−1 energy range. (1) Due to the bandwidth of the REMPI laser we were unable to resolve the rotational distribution of the νx=0. Therefore, we have performed depletion spectroscopy in the νx=0 trapped molecules using a diode laser at 682 nm to drive transitions from vX=0 to v=0 of the b1Πu potential. The pulsed dye laser frequency was set at the largest peak at 20966.9 cm−1. The experimental depletion spectrum, which is in good agreement with theoretical predictions, allows us to determine that 75\% the νx=0 molecules are in J= 0, 1 and 2 rotational states. (2)

Referências

1 PASSAGEM, H. F. et al. Formation of ultracold molecules induced by a high-power single-frequency fiber laser. Journal of Physics B, v. 50, n. 4, p. 045202-1-045202-6, Feb. 2017.
2 PASSAGEM, H. F. et al. Continuous loading of ultracold ground-state 85Rb2 molecules in a dipole trap using a single light beam. Physical Review Letters, v. 122, n. 12, p. 123401-1-123401-6, Mar. 2019.