Development of an optical standard based on an intercombination transition of strontium

Abstract

Ultracold atomic clouds driven by laser beams are ideally suited for the realization of quantum systems with unsurmounted purity. Their high degree of controlability, the possibility of shielding from perturbative interactions with the environment, the availability of resonances with extremely high Q-factors, and last not least, the miniaturizability are all good reasons for their use in quantum sensor applications. Atoms are already comercially used for time and frequency standards, gyroscopes, gravimeters, and interferometers. A particularly attractive atomic species for quantum sensor applications is strontium, because of the existence of ultranarrow transitions in the optical regime and the weak interatomic interactions.Our Research Group, with professors from both Instituto de Física de São Carlos and Escola de Engenharia de São Carlos, has a long-standing record in microwave frequency standards based on cesium atomic fountains. In recent times, our Time and Frequency team has been developing a compact clock using cold cesium atoms. Another team, which is devoted to Optical Strontium Lattices, constructed an experiment trapping and cooling strontium atoms to ultralow temperatures. The topic of this post-doctoral project is to study the feasibility of and to perform the first steps towards a new type of strontium-based frequency standard. In contrast to existing optical frequency standards interrogating clock-transitions in atoms stored in optical lattices, our approach will be to interrogate the transition via a high-finesse optical cavity in which the atoms are stored and to which the stable laser-oscillator is locked.The experiments will be performed by Dr. Sharafudeen, who applies with this proposal for a post-doc position from FAPESP. He is a very motivated young PhD student currently at the South China University of Technology, China. With his strong background the physics of cold atoms, working at the interface the time and frequency standard and the strontium lattice projects, he will help to inforce the technical and conceptual cooperation of the respective teams. (AU)