CAREER: Connecting Remote Atomic Quantum Registers via Entanglement

The internet has revolutionized society, and a quantum internet would enable further revolutionary advances based on information processing with profoundly new capabilities. For example, a quantum internet could facilitate scaling up quantum computers by linking modules together; it may enable new, more sensitive measurement devices; and it would provide a platform for secure communication based on quantum protocols. A key difference between classical and quantum networks is that quantum networks will utilize quantum states with stronger-than-classical correlations, called entangled states, that can be shared between network nodes. To enable some of the most compelling applications, entanglement will need to be distributed, stored, and manipulated at multiple network nodes. This is a daunting challenge, as entanglement is quite fragile and the quantum information encoded in entangled states is easily lost. This project will develop new tools for quantum networking based on arrays of individually trapped neutral atoms. The atoms will form a quantum register that can store entanglement and process quantum information. Furthermore, two or more registers will be linked by using a light-matter interface to distribute entanglement via single photons. Demonstrating these capabilities will constitute an important step towards building a quantum internet and will elucidate the physics and engineering of entanglement distribution. This research program is integrated with educational and outreach efforts to increase participation and awareness in quantum science. The educational and outreach activities will highlight demonstrations of quantum experiments in several venues. Arrays of individually trapped atoms have recently become a promising platform for quantum information processing and quantum simulation. This project will expand the range of applications for trapped atoms by exploring new quantum networking methods. This project will combine arrays of atoms with nanophotonic cavities that operate at telecom wavelengths to facilitate long-distance entanglement distribution. Processing quantum information within an array while generating entanglement between distant arrays will enable several possible applications for quantum networks such as distributed quantum computing, enhanced quantum sensing, and intercontinental quantum communication. This team aims to make progress towards these applications by demonstrating high-speed multiplexed entanglement generation with rates that are much faster than the decoherence rate of the nodes, and creating multiple entangled Bell pairs between registers that are separated by 50 kilometers. Techniques developed in this project can also expand the toolkit for quantum simulation, for example, by using this approach to study condensed matter physics models with quantum simulation architectures in which interactions are mediated by photons in a photonic crystal waveguide. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.