ExpandQISE Track 1: Quantum information exchange over spatially-multimode and multi-core optical fibers

University Of Texas At Arlington, Arlington TX

Investigators

Abstract

Non-technical description: Quantum communication uses fundamental laws of physics to securely exchange private information over untrusted networks and to establish quantum correlations among distant network nodes, which could be used for high-performance distributed quantum computing and ultra-precise quantum sensing. The capacity of quantum communication links is limited by the unavoidable losses of optical fibers connecting the nodes, and the only way to grow the quantum information exchange rate at a given distance is to increase the number of degrees of freedom (modes) over which the information is transmitted. While polarization and frequency / time modes have already received a lot of attention, one untapped resource for quantum information exchange over long fiber links is the spatial degrees of freedom of light in few-mode, multimode, and multi-core optical fibers. In this project, the research team harnesses the spatial degrees of freedom of light for carrying the quantum information over significant distances in optical fibers. Several types of high-capacity quantum communication links are investigated, ranging from a set of totally independent spatial quantum channels to links using spatial modes for high-dimensional data encoding. The project pairs University of Texas at Arlington, which has a nascent Quantum Information Science and Technology (QISE) program, with well-established and vibrant QISE research effort at Northwestern University. Through the joint research and student exchange, as well as collaboration with industrial and worldwide partners, the students of all levels, including those of underrepresented groups, are being trained at the forefronts of quantum science and optical communications. This collaborative work and the associated broad public and K-12 outreach activities, such as high-school summer camps and Engineering Week’s open lab visits and demos, aim to establish University of Texas at Arlington as a center for the emerging and productive QISE research community in North Texas. Technical description: This project’s goal is to increase the quantum communication capacity by exploiting spatial degrees of freedom of optical fibers. It extends the methods used in classical space-division multiplexing to the quantum domain to develop several types of high-capacity quantum communication links. These range from a set of totally independent spatial quantum channels to links maintaining full spatial coherence across many fiber modes or cores for transmission of quantum information encoded in high-dimensional spatial Hilbert space. The project employs a systematic approach to real-time characterization and inversion of the input-output transfer matrix of an optical fiber to enable the delivery of parallel-channel or high-dimensional qubits over metroscale distances, thus dramatically increasing the quantum communication capacity or rate at such reach. These techniques may also enable the transmission of spatially-broadband quantum states (quantum images) over km-scale lengths of multimode fiber, which can be useful in quantum sensing and metrology applications. The work engages the students with several industrial partners on development of customized few-mode and multi-core fibers, as well as fiber in/out couplers. A field-test of the developed methods is to be conducted over installed fibers. 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.