Jane E. Nordholt

The oxygen isotopic composition of the sun inferred from captured solar wind

The Sun is highly enriched in the most abundant isotope of oxygen, oxygen-16, relative to most other planetary materials. All planetary materials sampled thus far vary in their relative abundance of the major isotope of oxygen, 16O, such that it has not been possible to define a primordial solar system composition. We measured the oxygen isotopic composition of solar wind captured and returned to Earth by NASA’s Genesis mission. Our results demonstrate that the Sun is highly enriched in 16O relative to the Earth, Moon, Mars, and bulk meteorites. Because the solar photosphere preserves the average isotopic composition of the solar system for elements heavier than lithium, we conclude that essentially all rocky materials in the inner solar system were enriched in 17O and 18O, relative to 16O, by ~7%, probably via non–mass-dependent chemistry before accretion of the first planetesimals.

Practical Free-Space Quantum Key Distribution over 1 km

A working free-space quantum key distribution system has been developed and tested over an outdoor optical path of {approximately}1 km at Los Alamos National Laboratory under nighttime conditions. Results show that free-space quantum key distribution can provide secure real-time key distribution between parties who have a need to communicate secretly. Finally, we examine the feasibility of surface to satellite quantum key distribution. {copyright} {ital 1998} {ital The American Physical Society}

Long-Distance Decoy-State Quantum Key Distribution in Optical Fiber

The theoretical existence of photon-number-splitting attacks creates a security loophole for most quantum key distribution (QKD) demonstrations that use a highly attenuated laser source. Using ultralow-noise, high-efficiency transition-edge sensor photodetectors, we have implemented the first version of a decoy-state protocol that incorporates finite statistics without the use of Gaussian approximations in a one-way QKD system, enabling the creation of secure keys immune to photon-number-splitting attacks and highly resistant to Trojan horse attacks over 107 km of optical fiber.

Daylight quantum key distribution over 1.6 km

Quantum key distribution (QKD) has been demonstrated over a point-to-point 1.6-km atmospheric optical path in full daylight. This record transmission distance brings QKD a step closer to surface-to-satellite and other long-distance applications.

Optical networking for quantum key distribution and quantum communications

Modern optical networking techniques have the potential to greatly extend the applicability of quantum communications by moving beyond simple point-to-point optical links and by leveraging existing fibre infrastructures. We experimentally demonstrate many of the fundamental capabilities that are required. These include optical-layer multiplexing, switching and routing of quantum signals; quantum key distribution (QKD) in a dynamically reconfigured optical network; and coexistence of quantum signals with strong conventional telecom traffic on the same fibre. We successfully operate QKD at 1310 nm over a fibre shared with four optically amplified data channels near 1550 nm. We identify the dominant impairment as spontaneous anti-Stokes Raman scattering of the strong signals, quantify its impact, and measure and model its propagation through fibre. We describe a quantum networking architecture which can provide the flexibility and scalability likely to be critical for supporting widespread deployment of quantum applications.

Dense wavelength multiplexing of 1550 nm QKD with strong classical channels in reconfigurable networking environments

To move beyond dedicated links and networks, quantum communications signals must be integrated into networks carrying classical optical channels at power levels many orders of magnitude higher than the quantum signals themselves. We demonstrate the transmission of a 1550 nm quantum channel with up to two simultaneous 200 GHz spaced classical telecom channels, using reconfigurable optical add drop multiplexer (ROADM) technology for multiplexing and routing quantum and classical signals. The quantum channel is used to perform quantum key distribution (QKD) in the presence of noise generated as a by-product of the co-propagation of classical channels. We demonstrate that the dominant noise mechanism can arise from either four-wave mixing or spontaneous Raman scattering, depending on the optical path characteristics as well as the classical channel parameters. We quantify these impairments and discuss mitigation strategies.

Free-space quantum-key distribution

Nonproliferation and International Security,Los Alamos, NM 87545(February 1, 2008)A working free-space quantum key distribution (QKD)system has been developed and tested over a 205-m indooroptical path at Los Alamos National Laboratory under fluo-rescent lighting conditions. Resultsshow that free-space QKDcan provide secure real-time key distribution between partieswho have a need to communicate secretly.PACS Numbers: 42.79.Sz, 03.65-w

Long-distance quantum key distribution in optical fibre

Use of low-noise detectors can both increase the secret bit rate of long-distance quantum key distribution (QKD) and dramatically extend the length of a fibre optic link over which secure keys can be distributed. Previous work has demonstrated the use of ultra-low-noise transition-edge sensors (TESs) in a QKD system with transmission over 50?km. In this study, we demonstrate the potential of the TESs by successfully generating an error-corrected, privacy-amplified key over 148.7?km of dark optical fibre at a mean photon number ? = 0.1, or 184.6?km of dark optical fibre at a mean photon number of 0.5. We have also exchanged secret keys over 67.5?km that is secure against powerful photon-number-splitting (PNS) attacks.

Practical long-distance quantum key distribution system using decoy levels

Quantum key distribution (QKD) has the potential for widespread real-world applications, but no secure long-distance experiment has demonstrated the truly practical operation needed to move QKD from the laboratory to the real world due largely to limitations in synchronization and poor detector performance. Here, we report results obtained using a fully automated, robust QKD system based on the Bennett Brassard 1984 (BB84) protocol with low-noise superconducting nanowire single-photon detectors (SNSPDs) and decoy levels to produce a secret key with unconditional security over a record 140.6 km of optical fibre, an increase of more than a factor of five compared with the previous record for unconditionally secure key generation in a practical QKD system.

Present and future free-space quantum key distribution

Free-space quantum key distribution (QKD), more popularly know as quantum cryptography, uses single-photon free-space optical communications to distribute the secret keys required for secure communications. At Los Alamos National Laboratory we have demonstrated a fully automated system that is capable of operations at any time of day over a horizontal range of several kilometers. This has proven the technology is capable of operation from a spacecraft to the ground, opening up the possibility of QKD between any group of users anywhere on Earth. This system, the prototyping of a new system for use on a spacecraft, and the techniques required for world-wide quantum key distribution will be described. The operational parameters and performance of a system designed to operate between low earth orbit (LEO) and the ground will also be discussed.