Quantum Information Networks

Quantum Communication

                             

Quantum information science combines two of the great scientific and technological revolutions of the 20th century, quantum mechanics and information theory. According to the National Science and Technology Council’s 2008 report  “A Federal Vision for Quantum Information Science”, quantum information science will enable a range of exciting new possibilities including: greatly improved sensors with potential impact for mineral exploration , improved medical imaging and a revolutionary new computational paradigm that will likely lead to the creation of computation device capable of efficiently solving problems that cannot be solved on a classical computer.

One of the fundamentally important research areas involved in quantum information science is quantum communications, which deals with the exchange of information encoded in quantum states of matter or quantum bits (known as qubits) between both nearby and distant quantum systems. Our Quantum Communication project performs core research on the creation, transmission, processing and measurement of optical qubits – the quantum states of photons, with particular attention to application to future information technologies.
           

Single photons at telecommunication wavelengths can be detected with higher efficiency with our frequency up-conversion detector.

In the past few years, we have undertaken an intensive study of quantum key distribution (QKD) systems for secure communications. Specifically, we demonstrated high-speed QKD systems that generate secure keys for encryption and decryption of information using a one-time pad cipher, and extended them into a 3-node quantum communications network. We have demonstrated the strengths and observed the limitations of QKD systems and networks. One such limitation is the effective communication distance of a point-to-point QKD system, which is about 100 km. Quantum repeaters represent a promising solution to this distance limitation. It enables quantum information exchange between two distant quantum systems including quantum computers. Though quantum repeaters are conceptually feasible, there are tremendous challenges to their development. Our goal in this area is to identify the problems, find potential solutions and evaluate their capabilities and limitations for future quantum communication applications.

In summary, we perform research and development (R&D) in quantum communication and related measurement areas with an emphasis on applications in information technology. Our R&D is aimed to promote US innovation, industrial competitiveness and enhance the nation’s security. This website shows the footprint of our R&D efforts in the past few years.

For more information concerning this program, please contact project leader Dr. Xiao Tang (xiao.tang@nist.gov).

           

Keywords: quantum communication, quantum measurement science, entangled photons, quantum teleportation and repeaters, free space optics, quantum cryptography, photon source/detectors.