Thursday, July 21, 2011
Physicists working to deliver quantum information to the home
Scientists are now working on ways to combine quantum data with the classical data in fiber optic networks in order to increase security and deliver high-end data to the home. In a new study, researchers have shown how quantum and classical data can be interlaced in a real-world fiber optics network, taking a step toward distributing quantum information to the home, and creating a quantum internet.
The physicists, Iris Choi, Robert Young, and Paul Townsend, from the Tyndall National Institute at the University College Cork in Cork, Ireland, have published their study on combining quantum and conventional data in a recent issue of the “New Journal of Physics.”
According to Townsend “I believe that our work constitutes the first really hard-nosed, pragmatic attempt to address the question of whether quantum key distribution can work on a real fiber-to-the-home network. The new scheme that we have developed and tested demonstrates that the answer is ‘yes it can.’ I say pragmatic and hard-nosed because we have taken a widely deployed classical FTTH system and have adapted QKD to interwork with it, leaving the design of the classical part of the system essentially unchanged.”
The largest challenge in transferring quantum bits in real-world networks is overcoming the crosstalk between the classical and quantum channels. Crosstalk is generated by spontaneous Raman scattering of photons in the optical fiber. Since the classical channels involve strong laser pulses while the quantum information is carried by single photons, the crosstalk primarily affects the quantum channel, making the error rate so high that the quantum channel cannot operate.
While the feasibility of transferring qubits on modern fiber-to-the-home networks has previously been demonstrated, this is the first time that researchers have investigated how the operation would work in a real-world network. Quantum bits are also of great interest to data security researchers.
Scientists at the Los Alamos National Lab have been working to utilize quantum bits as a means to secure sensitive information on a network.
LANL has developed Quantum Enabled Security, a revolutionary new cybersecurity capability using quantum communications integrated with optical communications to provide a strong, innate security foundation at the photonic layer for optical fiber networks. In QES, quantum connections are established using secret random numbers shared between authorized users. These numbers are then utilized to generate frequently changing secret codes to spread conventional communications in time, frequency or both.