Coherence related phenomena in lithium molecules by all- optical multiple resonance spectroscopy

Ian Stevenson

I present spectroscopic data on ultracold lithium-rubidium molecules in a dual species magneto-optical-trap in order to find suitable intermediate states to transfer population to the rotational, vibrational and electronic ground state via a stimulated Raman process. First, I improved the accuracy of the energetic location of the ground state by two orders of magnitude using photoassociation as a spectroscopic tool to measure the energy of bound states relative to the scattering continuum. Second, we studied the d 3Π-D 1Π and A 1Σ+ -b 3Π0+ excited electronic manifolds with a combination of resonantly-enhancedmulti-photon-ionization and depletion spectroscopy finding suitable singlet-triplet mixed states to use in the Raman transfer scheme. Finally, I demonstrate robust optical phase locked loops to maintain the coherence between the two lasers required for the Raman process.

S.D. Kramer, Jack Phillip Young, G. S. Hurst +1 more

R. A. W. Maier, C. Marzok, Claus Zimmermann +1 more

We study rf spectroscopy of a lithium gas with the goal to explore the possibilities for photoemission spectroscopy of a strongly interacting $p$-wave Fermi gas. Radio-frequency spectra of quasibound $p$-wave molecules and of free atoms in the vicinity of the $p$-wave Feshbach resonance located at $159.15$ G are presented. The spectra are free of detrimental final-state effects. The observed relative magnetic-field shifts of the molecular and atomic resonances confirm earlier measurements realized with direct rf association. Furthermore, evidence of molecule production by adiabatically ramping the magnetic field is observed. Finally, we propose the use of a one-dimensional optical lattice to study anisotropic superfluid gaps as most direct proof of $p$-wave superfluidity.

Angelos Lazoudis, Jianbing Qi, Frank C. Spano +6 more

Warren S. Warren, Ahmed H. Zewail

Jianbing Qi, Frank C. Spano, Guenadiy Lazarov +4 more

In recent years, coherent effects in atomic and molecular systems have been studied extensively, especially in several new classes of effects, such as lasing without inversion (LWI), electromagnetically induced transparency (EIT), coherent population trapping (CPT), AC Stark effect and Autler-Townes (AT) splitting in multilevel systems. The AC stark effect and Autler-Townes splitting in molecules have only been investigated recently. We demonstrate AC stark effect and Autler-Townes (AT) splitting in a lithium molecule using cw multi-photon spectroscopy. The excited upper level of the $G^{1}\\Pi_{g}$ is prepared by the optical-optical double resonance (OODR) excitation. The OODR line is split in the presence of a third coupling laser, which couples the upper level to an another intermediate level when the coupling laser is on or near resonance transition. The AT line shape consists of the superposition of $|M_{J}|$ components which have been resolved for $G^{1}\\Pi_{g}(v=12, J=3,f)$. We find that the AT splittingis linearly proportional to $|M_{J}|$, which allows the excitation of molecules with a selected $|M_{J}|$ level. The AC Stark shift of the OODR line is observed when the coupling laser is detuned from the resonance transition.