RAISE-EQuIP: Quantum repeater for long-distance quantum communication enabled by non-Gaussian cluster states on a scalable hybrid aluminum nitride and silicon nanophotonic platform

University Of Arizona, Tucson AZ

Investigators

Abstract

RAISE-EQuIP: Quantum repeater for long-distance quantum communication enabled by non-Gaussian cluster states on a scalable hybrid aluminum nitride and silicon nanophotonic platform Saikat Guha, Linran Fan, Dan Kilper, University of Arizona Principles from quantum physics will enable far superior computational capabilities, better sensors and secure communications that are provably unbreakable by any adversary. Most of these advancements will be enabled by a new information resource called quantum entanglement. One of the most important building blocks to realize a quantum-enabled network information infrastructure that is capable of generating and distributing entanglement at high rates over long distances is the quantum repeater a quantum enabled processor that will sit at the node of the future quantum internet, augmenting the current-day network router. Our project?s goal is to research, develop and test a design for the quantum repeater, which will be realized compactly in an integrated photonic platform that produces complex many-photon entangled states on demand. The successful completion of this project will enable various applications of shared entanglement, including future-proof secure communications and multi-party secure computations, entanglement-assisted distributed sensors for far superior imaging and remote sensing, and will enable new science discoveries in areas such as chemistry and high-energy physics by letting us experiment with entangled states larger than any created so far. Even though our main thrust is to research a scalable on-chip design of a quantum repeater, the theoretical work will help us develop a deep understanding of building general and special-purpose quantum processors that use photons to encode the qubit, whereas the versatile nanophotonic platform we will design will be of value to various quantum enabled photonic information processing with applications to distributed sensing and distributed cloud-based quantum computing. Because of the highly-interdisciplinary nature of quantum information science, and our project team in particular, our education and outreach program will have a particularly broad impact in training a diverse and strong workforce at the intersection of physics, optical sciences, electrical and material science and engineering, computer network theory, and mathematics. The biggest challenge in building a quantum repeater has been the lack of good-quality quantum memories, high-rate good-fidelity matter-photon entanglement sources, and high-efficiency quantum-state-preserving frequency interconversion so as to make a telecom-wavelength quantum photon be compatible with the quantum storage and processing units. Our project?s goal is to research and develop a design of a quantum repeater that does not need quantum memories or quantum interconversion, but uses an integrated photonic source of locally-generated complex entangled states of many photonic modes to replace the action of the quantum memory by providing virtual storage of a logical quantum bit (qubit) using quantum error correction against photon loss. Such repeaters, known as all-photonic repeaters, have been proposed and recently researched by members of our team. But existing work on such repeaters need millions of near-perfect single-photon sources and detectors, along with extremely low-loss linear-optical waveguides be supplied at each repeater node. Our key insight is to develop an alternative scheme that leverages recently-demonstrated photonic multi-mode-squeezed entangled states of thousands of modes as the cluster source, but built compactly on a hybrid Aluminum Nitride - Silicon photonic platform, and use photon number detection on a subset of those modes to cast that into a universal-quantum-capable coded cluster state and develop a new logical qubit encoding into that "non-Gaussian" cluster state in a so-called Schrodinger-cat-like qubit basis. The goals of this project are: (1) establishing the theoretical design principles of a technologically-feasible all-photonic quantum repeater based on a continuous-variable (CV) entangled cluster source, (2) developing a compact, versatile integrated nanophotonic platform for generating and manipulating CV cluster states, (3) realizing direct on-demand generation of non-Gaussian universal clusters at high rates, and (4) the first measurement of entanglement distribution over one quantum repeater link that exceeds the fundamental direct-transmission rate upper limit for entanglement generation. 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.