Optical tweezer arrays of neutral atoms have emerged as a promising platform for studying quantum physics. These individual atoms can be carefully prepared in single quantum states, and easily manipulated with microwaves and lasers. MHz scale interactions are accessible at several micron scale distances by exciting these atoms to Rydberg states. These arrays can also be created in arbitrary 2D geometries with the use of a spatial light modulator. Adding the capability of a second species opens new possibilities in non-destructive measurement and quantum simulation of bipartite systems with widely tunable parameters. In this thesis, we describe our efforts to build a flexible platform for studying quantum phenomena utilizing two species of atoms, sodium and cesium. In particular, we discuss the laser technology and setups required to create dual species optical tweezer arrays. These arrays are made defect-free with real-time rearrangement of atoms using a separate set of tweezers created with acousto-optical deflectors. We then describe how to excite these atoms coherently to the Rydberg state with coherence times in Cs as long as 20 microseconds. With these techniques established, we are able to probe an Ising critical point in 1D and 2D systems with up to 81 atoms. In particular, we measure and confirm the value of the universal critical exponent,
η, via adiabatic preparation of the ground state at the critical point. Then, we measure the interactions between sodium and cesium atoms setting the stage for future experiments. Lastly, a theoretical proposal is presented where Rydberg atoms can be used to enhance the interaction rates of ultracold polar molecules, as well as measure their states non-destructively.
Neutral atoms trapped in optical lattices are promising candidates for quantum information processing and quantum simulation. Over the last decades, elegant tools for the manipulation of the internal and external states of optically trapped atoms have been developed. The crucial capability of scalable internal state readout in these systems, however, still relies on destructive methods. In spite of the important role of near-resonant illumination for the manipulation and detection of atoms in the lattice, there also exists a significant lack of studies on the heating and cooling dynamics of optically trapped atoms interacting with near-resonant light. An in-depth understanding of the heating and cooling processes is essential to finding the conditions of illumination that enable the non-destructive internal state readout of multiple atoms. This work presents an experimental system to cool, trap, manipulate, and detect the internal and external states of a small ensemble of 87Rb neutral atoms trapped in a one-dimensional optical lattice. A high photon detection efficiency in our experimental system allows for fast fluorescence imaging with acquisition times of 20 ms and fast position determination of atoms in the optical lattice with an accuracy of ∼ 40 nm. Using this experimental system, we investigate the heating dynamics of a neutral atom trapped in a standing wave dipole trap illuminated by a single near-resonant laser beam. A theoretical description to describe our measurements is provided in two experimentally relevant regimes. First, we consider the case of a weak near-resonant beam and later the case of off-resonant illumination. From this analysis, we find settings for the illumination light which allows an atom to scatter many photons before it is expelled from the trap. Building on these results we demonstrate simultaneous, non-destructive determination of the internal state of spatially resolved atoms trapped in a one-dimensional optical lattice with a fidelity of 98.6 ± 0.2% and a survival probability of 99.0 ± 0.2%. During the readout process, less than 2% of the atoms change their initial ground state. In order to determine the state of atoms that are not spatially resolved, a novel image analysis technique is presented. The technique uses Bayesian methods, which include the statistics of the detected photons as well as the response from the EMCCD camera. The Bayesian method is implemented on experimental data for atoms trapped in a one-dimensional optical lattice and its accuracy is tested by numerical simulations. In addition, an extension of this algorithm for atoms trapped in two-dimensional lattices is provided. Finally, the non-destructive state detection method is utilized as a tool for the state determination following the coherent control of the internal and external states of atoms in the optical trap. Here Raman sideband cooling is implemented and utilized in an atomic compression sequence for the creation of a small and dense atomic ensemble. These techniques will play an important role in experiments studying the collective light interaction of the atomic ensemble in a recently added optical fiber cavity.
Most neutral atom quantum computing experiments rely on destructive state detection techniques that eject the detected qubits from the trap. These techniques limit the repetition rate of these experiments due to the necessity of reloading a new quantum register for each operation. \n \nWe address this problem by developing reusable neutral atom qubits. Individual Rubidium 87 atoms are trapped in an optical lattice and are held for upwards of 300 s. Each atom is prepared in an initial quantum state and then the state is subsequently detected with 95% fidelity with less than a 1% probability of losing it from the trap. This combination of long storage times and nondestructive state detection will facilitate the development of faster and more complex quantum systems that will enable future advancements in the field of quantum information.