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Results for “clocks”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Realizing spin squeezing with Rydberg interactions in an optical clock
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Frequency ratio of the 229mTh nuclear isomeric transition and the 87Sr atomic clock
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Universal quantum operations and ancilla-based read-out for tweezer clocks
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Temperature dependence of energy transport in the Z 3 chiral clock model
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Unsafe at Any Clock Speed: The Insecurity of Computer System Design, Implementation, and Operation
It appears that there are enormous differences of opinion as to the probability of a [system failure]. The higher figures come from the working engineers, and the very low figures from management. When playing Russian roulette the fact that the first shot got off safely is little comfort for the next. [T]here have been recent suggestions by management to curtail elaborate and expensive tests as being unnecessary. However, this must be resisted. The proper way to save money is to curtail the number of requested changes, not the quality of testing for each.
Implementation of quantum key distribution and quantum clock synchronization via time bin encoding
Quantum key distribution allows for a provably secure transmission of cryptographic keys over an optical channel. Encoded polarization states or time-bin degree of freedom have been used for successful demonstrations. However, photon losses in long fibers, slow single photon detectors, and detector dark counts significantly limit the overall bit rate. Improving key throughput and reducing the overhead of key reconciliation remain as major challenges. Methods which utilize multiple time bins allow for multiple key bits to be encoded in a single photon, thus increasing the fidelity of transmitted keys and decreasing the overhead of key reconciliation in real-world conditions. Previous implementations of these methods required that Alice and Bob share a time reference by sharing a dedicated classical channel used for synchronization. This work presents a technique that allows two parties to exchange time-bin encoded photons without the need for synchronized time references. Our technique uses a framing protocol which allows Alice to encode a time reference along with a key which is determined by Alice before transmission. Security can be achieved by monitoring the visibility of a pair of Franson interferometers, using decoy pulses and measuring the round trip time between Alice and Bob. The bit rate of this technique is limited only by the recovery time of the detector and the speed of the modulation electronics. We experimentally demonstrate a raw bit rate of 5Mb/s over an optical channel with 55dB of loss, which is competitive with current research. We also demonstrate absolute timing synchronization with an accuracy of 20ps.
Reconstitution of an intact clock reveals mechanisms of circadian timekeeping
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Bayesian modeling reveals metabolite‐dependent ultrasensitivity in the cyanobacterial circadian clock
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Progress Towards a Multi-ion Optical Clock Based on a Linear Chain of Yb Ions.
Abstract not provided.
Detection and Localization of an Adversarial GPS Interference Source Based on Clock Signatures.
Abstract not provided.