Single Atom Detection via Transparency Techniques

Abstract

Over the last decade, atom arrays have emerged as a powerful platform for quantum technologies, enabling applications in simulation, computation, metrology and sensing. While having many unique features especially useful for quantum computing, there are areas where this platform can be improved, and this thesis presents tools developed to enhance its speed. The first tool developed is a fast non-destructive qubit readout, intended for improving computational speed of this platform, in particular, mid-circuit measurements. This method utilizes tweezers filled with ensembles of atoms to collectively readout a single Rydberg qubit via Electromagnetically Induced Transparency (EIT) improving readout speed by several orders of magnitude compared to conventional methods. We test several configurations of these ensemble detectors and provide an understanding of the underlying physical mechanisms in each scenario. The second tool developed is a method for single-atom loading and imaging in high magnetic fields, based on combination of fluorescence imaging, responsible for detection, and D2 EIT cooling, responsible for preserving the atoms during detection. This tool, combined with continuous loading technique, has the potential to reduce the experimental cycle time of the neutral atom platform by several orders of magnitude. While work in this thesis primarily focused on developing more efficient quantum computing apparatus for single atom arrays, an accidental discovery during this research led to the creation of a Bose-Einstein Condensate (BEC) inside a micro-ensemble using only polarization gradient cooling (PGC). This finding challenges the longheld belief that PGC alone is insufficient to generate BEC, and illustrates the non-linear nature of the research process, where interesting discoveries can occur unexpectedly.