My research explores methods to gain control over individual atoms for computing, communications and sensing technology. When isolated, atoms display manifestly quantum mechanical behavior, routinely doing things like being in two places at the same time or getting entangled with their neighbors. In macroscopic clumps like computer chips, these effects are washed out. However, there is strong motivation to try to build computers and communications devices in such a way that the quantum properties of individual atoms can be retained because devices operating according to quantum laws can offer dramatic advantages in terms of power and security.
We focus on two types of isolated atoms: atoms levitated in vacuum and impurities in otherwise perfect crystals. In both cases, we use nano-fabricated optical structures as a microscope that allows us to resolve these atoms, and to prepare and measure their quantum states using photons. Additionally, these photons can be used to create interactions and entanglement between atoms.
In one research direction, we are using nanophotonic circuits to spatially isolate and address individual or small clusters of rare earth ion dopants in crystalline hosts for use as single photon sources and quantum memories. These are crucial ingredients for quantum repeater systems for quantum communications networks. In connection with this research, we are also working on basic engineering for other components of a complete quantum repeater architecture, such as high-Q photonic crystal cavities, fiber-chip interconnects, wavelength converters and ultra-low-noise single photon detectors.
In a second research direction, we are developing techniques to laser-cool and trap large arrays of atoms levitated in vacuum. The potential to create very uniform and homogeneous arrays with long-range photon-mediated interactions creates many possibilities for studies of quantum many-body physics and new quantum computing architectures.