100 years after Einstein’s landmark paper, optical tweezer technology could confirm the theory of classical Brownian motion in details that Einstein missed when he first proposed it a century ago. This research is reported today in a special Einstein Year issue of the New Journal of Physics (www.njp.org) published jointly by the Institute of Physics and the German Physical Society (Deutsche Physikalische Gesellschaft).
“Optical tweezers” use a focused laser beam to trap and study microscopic objects, such as the individual bio-molecules that power muscle cells and propel sperm, and those that read the genetic code. The device is disturbed, however, by a subtle effect in Brownian motion known as the back-flow effect.
100 years ago in 1905, Einstein published a landmark paper on Brownian motion. He theorised that it is the constant buffeting of microscopic particles that goes on in any fluid as the fluid molecules randomly knock those particles around. He missed the subtle "back-flow effect" in which the very movement of a particle disturbs the water which ultimately bounces back to nudge the particle in return. "Its like a boat that tries to stop, and then is pushed by its stern wave when that wave catches up with the boat," explains Henrik Flyvbjerg of Risø National Laboratory in Denmark. "Optical tweezers sense the back-flow effect," adds Flyvbjerg, "but that also means it can be studied with them."
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The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
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With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
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An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
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Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
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08.12.2017 | Information Technology
08.12.2017 | Information Technology