By exploiting the weird quantum behavior of atoms, physicists at the Commerce Department’s National Institute of Standards and Technology (NIST) have demonstrated a new technique that someday could be used to save weeks of measurements needed to operate ultraprecise atomic clocks. The technique also could be used to improve the precision of other measurement processes such as spectroscopy.
The technique, described in today’s issue of Science, effectively turns atoms into better frequency sensors. Eventually, the technique could help scientists measure the ticks of an atomic clock faster and more accurately. Just as a grandfather clock uses the regular swings of a pendulum to count off each second of time, an atomic clock produces billions of ticks per second by detecting the regular oscillations of atoms. The trick to producing extremely accurate atomic clocks is to measure this frequency very precisely for a specific atom.
In the latest experiment, the scientists used very brief pulses of ultraviolet light in a NIST-developed technique to put three beryllium ions (charged atoms) into a special quantum state called entanglement. In simple terms, entanglement involves correlating the fates of two or more atoms such that their behavior--in concert--is very different from the independent actions of unentangled atoms. One effect is that, once a measurement is made on one atom, it becomes possible to predict the result of a measurement on another. When applied to atoms in an atomic clock, the effect is that n entangled atoms will tick n times faster than the unentangled atoms.
Laura Ost | NIST
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Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
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