Generation, Control and Storage of Broadband Transverse-Mode-Entangled Photons

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Photons, the fundamental particles of light, can be “entangled” with each other such that the measurement of one instantaneously changes the state of the other. Entangled photons can be used to enhance our ability to communicate securely and to image sensitive biological materials, amongst other applications. While techniques to generate photons entangled in polarization, frequency, and time are well-developed, there is much to explore in the generation of photons entangled in their shape, or spatial mode. In addition, building an efficient memory that allows us to store and retrieve entangled photons on demand would allow communication and sensing applications to be much more efficient. The research team will investigate optical fiber as a source of spatial-mode-entangled photons and the use of hot atomic gases as storage media for such photons. Graduate students will be trained in state-of-the-art quantum optics experiment and theory, and group members will actively support efforts to enhance minority representation in the sciences and create new hands-on laboratory modules for instruction of undergraduate students. The research team will develop methods based on optical fibers and atomic ensembles to enhance control over quantum correlations in broadband photonic quantum sources, with a focus on enhancing entanglement dimensionality, quantum memory operation, and scalability in four-wave-mixing-based systems. An optical fiber platform will be explored for hybrid entanglement, multimode interference, and highly multimode entanglement. The fundamental role of broadening mechanisms in determining memory efficiency and lifetime for broadband quantum states will be explored both theoretically and experimentally through an atomic ensemble platform, and methods will be developed to extend the memory lifetime, enable transverse mode storage and retrieval, and generate photon pairs via Raman-mediated spontaneous four-wave mixing. The development of transverse-mode entanglement in optical fiber will provide new resources for quantum processing by enabling a high-dimensional space for enhanced quantum protocols in a platform naturally suited for coupling to other fibers for long-distance transmission. Investigations of quantum memory operation in the broadband regime of such sources, and explorations of new fiber-based sources, will provide tools for enhanced efficiency and scalability. These efforts will help advance the overall field of quantum information science towards the broadly impactful goals of improved computation, communication, and sensing. 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.