The use of strontium in an atom interferometer presents the opportunity to perform detailed measurements of gravitational fields, rotation rates, and clock transitions as well as other natural phenomena. Strontium can be particularly effective in atom interferometry experiments for two reasons. The first is that the intrinsic magnetic properties of strontium result in less sensitivity of the transition frequencies to magnetic noise, allowing for better measurements. Second, strontium atoms can be cooled to a lower temperature just through ordinary Doppler cooling than other atoms typically used in interferometry (e.g., rubidium). A lower temperature means less initial kinetic energy and hence lower spatial dispersion over the course of an experiment. A magneto-optical trap consisting of two primary cooling lasers and two repump lasers cools and confines strontium atoms for use in the interferometer. This thesis focuses on the repump lasers and includes the design and performance of the optical system that frequency stabilizes each laser. The system demonstrated the ability to simultaneously frequency lock the two repump lasers to the degree necessary to form a strontium magneto-optical trap.

Sep 1, 20220 citations

Experimental set-up for realising long-range interaction using strontium atoms in an optical lattice

Marco Menchetti

Ultracold interacting gases represent a new and exciting frontier for technological applications, such as quantum information processing, and they also offer an ideal test bench for condensed matter systems. \nThis work examines the case of atoms in the alkaline earth metal family. These atoms can exhibit long-range dipolar interactions, generated via coherent exchange of photons on the 3P0 ! 3D1 transition. In particular, the progress in realising an experiment to study this coherent exchange of atoms in bosonic strontium is discussed. A review of the experimental techniques developed over the last 50 years to cool, manipulate and study atoms and molecules used in long-range interaction experiments is given from a historical viewpoint. Techniques to laser cool and trap atomic strontium are described, and a novel study of different geometries for magneto-optical traps (MOTs) is presented. \nThis thesis describes the long-range interaction strontium experiment under development at the University of Birmingham. In particular, the characterisation of a self assembled Zeeman slower is presented, along with a novel repump scheme for the first stage of cooling using the 3P0 ! 3D1 transition. \nThis work also reports the use of the 3P1 ! 3S1 transition to populate the 3P0 level, and the realisation of a monolithic (Interference Filter External \nCavity Diode Laser) IFECDL. \nThe new techniques that I present here have the potential to facilitate future studies of long-range interaction in strontium and other cold atoms experiments.

Jul 11, 20190 citations