Pump-probe study of the formation of rubidium molecules by ultrafast photoassociation of ultracold atoms

Abstract

An experimental pump-probe study of the photoassociative creation of translationally ultracold rubidium molecules is presented together with numerical simulations of the process. The formation of loosely bound excited-state dimers is observed as a first step towards a fully coherent pump-dump approach to the stabilization of Rb2 into its lowest ground vibrational states. The population that contributes to the pump-probe process is characterized and found to be distinct from a background population of pre-associated molecules.

Coherent control of ultracoldRb85trap-loss collisions with nonlinearly frequency-chirped light

“…Subsequent experiments [24][25][26][27][28] observed coherent transients in excitedstate molecules photoassociated with femtosecond pulses and there was some evidence for the production of ground-state molecules [25]. In contrast, our approach is to control the dynamics of ultracold atoms at large R using nanosecondtime-scale frequency-chirped pulses.…”

Production of ultracold molecules with chirped nanosecond pulses: Evidence for coherent effects

“…This has been motivated in large part by the desire to form ultracold molecules [6] with high efficiency and state specificity for their many potential applications in quantum information, precision spectroscopy, ultracold chemistry, and quantum dipolar systems. So far, experimental progress towards coherently controlled PA has been limited to control of the photodestruction of already existing ultracold molecules [7,8] and the observation of coherent transients in PA with femtosecond pulses [9,10]. In recent work, we have used frequency-chirped light on the nanosecond time scale to coherently control a closely related process, laser-induced inelastic collisions.…”

Ultrashort Pulse Characterization

“…Alternatively, one may ionize the molecules with a high frequency pulse and then detect the number of ions formed [9]. At a specific internuclear separation, the ionizing pulse spectrum can match the energy separation between excited and ionic state and a high ionic yield will only occur when the oscillating wave packet crosses that internuclear separation.…”