Compact 2D-MOT and 3D-MOT Systems for Portable Quantum Gravimeter and Quantum Simulator

Abstract

Cold atoms are extremely useful in a wide range of experiments, including atom interferometry, precision measurements, quantum simulation, and atomic clocks. The two-dimensional magneto-optical trap (2D-MOT) and three-dimensional magneto-optical trap (3D-MOT) act as cold atom sources. A 2D-MOT confines the motion of the thermal atom from two dimensions by using near resonant transition frequency laser beams exerting radiation pressure on the atoms in the light field. Because the atoms in this configuration are trapped only from two dimensions, they always have a velocity component in the third dimension, resulting in a cooling temperature of the order of μK. To get atoms down to a lower temperature, the cloud is transferred from a 2D-MOT to a 3D-MOT setup. A 3D-MOT setup is used to confine atoms in all three dimensions, resulting in temperatures lower than a 2D-MOT setup. In most laboratory based setups, 2D-MOT is used as the first stage of cooling, and 3D-MOT is the second stage of cooling. The 3D-MOT experimental setup designed in this thesis loads the atom in the trap directly from the background vapour pressure of rubidium, and the number of atoms in the trap is 2.8 x10^8. The goal of this thesis is to develop a platform for portable systems with better sensitivity outside the lab. Since these systems are the most commonly used systems for generating cold atoms, a compact design of these systems will result in a compact and portable design for Quantum Gravimeter and Quantum Simulator. The setups were used to generate a cloud of cold atoms with a large number of atoms in the cloud, which was then characterised to determine the best operating conditions for the system. The 3D-MOT setup was then used for Electromagnetically Induced Transparency experiments of a Ladder-type system followed by spectroscopy of highly excited Rydberg state of 87Rb. A Ladder-type system for excitation of the Rydberg state is used to generate an array of entangled neutral atoms for quantum information processing. The signal from the Rydberg spectroscopy was then used for frequency stabilisation of the coupling laser, also known as the Rydberg laser, used to excite the atom to a highly excited Rydberg state.