Configurable Entangled Photon Source for Quantum Networks

Quantum entanglement, a physical phenomenon in which two or more quantum systems share correlations even when separated by large distances, is an important resource for quantum information applications such as quantum computing and is critical for overcoming loss constraints that limit the transfer of quantum states across large distances. Despite their relative maturity in the field, entangled photon sources are still built primarily by graduate students, and there is significant variability among sources. Moreover, entangled photon sources lack flexibility, typically designed to output a single type of entangled state. General statement of how this problem is being addressed: We propose to develop a compact entangled photon source that can be programmed, or re-configured, to emit user-defined two- photon quantum entangled states (including both Bell states and non-maximally entangled states). The source design will be based on demonstrated entangled photon technologies and will incorporate proven optical engineering techniques for improved stability and reduced form factor. The project will leverage Qubitekk’s expertise in developing and commercializing entangled photon sources for Quantum Key Distribution systems. What is to be done in Phase I? The research proposed herein will facilitate the development of an entangled photon source that is significantly more versatile and reliable than purpose-built sources that are typically employed in quantum information applications. Specifically, the overall project goal is to design and build a source with the following attributes: programmable output, automatic optimization, and stable and reliable operation. This will be accomplished in multiple phases, beginning with the design, fabrication, and testing of a base entangled photon source. This will be followed with steps to make the source programmable so as to facilitate the access of any two-photon polarization-entangled state. Finally, a feedback loop will be implemented in order to drive the source to a specified state more quickly and accurately than could be achieved manually. Commercial applications and other benefits: The goal of this project is to advance entangled photon source technology to the point that it becomes widely available to the quantum information community. This is likely to enable advances in a variety of quantum information applications, including quantum security and quantum sensing. In addition, quantum entanglement is a resource required for linking quantum computing processors. Quantum computing has been identified by DOE as an important technology for advanced scientific computing.