Recent Comments

    Category Technology/Electronics

    Exotic states: How to spawn a “ring of exceptional points”

    September 10, 2015, Categories  Technology/Electronics, Physics

    A schematic drawing of how a ring of exceptional points (shown in white) can be spawned from a Dirac point (a dot), and thus change the dispersion from the normal, widely known conical shape into an exotic lantern-like shape Credit: Courtesy of the researchers

    A schematic drawing of how a ring of exceptional points (shown in white) can be spawned from a Dirac point (a dot), and thus change the dispersion from the normal, widely known conical shape into an exotic lantern-like shape Credit: Courtesy of the researchers

    Researchers create exotic states leading to new sensors and optical devices. The Dirac cone, named after Paul Dirac, started as a concept in particle and high-energy physics and has recently became important in condensed matter physics and material science. It describes aspects of graphene, suggesting the possibility of applications across various fields. Now physicists have found another phenomenon produced by the Dirac cone: It can spawn a “ring of exceptional points...

    Read More

    Ultrafast Uncoupled Magnetism in Atoms: new step towards Computers of the Future

    September 10, 2015, Categories  Physics, Technology/Electronics

    Couplings of the gadolinium spin system.

    Couplings of the gadolinium spin system. (a) The interaction of the different heat baths in an extended three-temperature model. After infrared laser excitation of the valence electrons, the whole system equilibrates by exchanging energy and momentum, indicated by the double arrows. The 5d and 4f spin systems couple via inter- and intra-atomic exchange, where the intra-atomic exchange Jint=130 meV is much larger than the largest (nearest neighbour) inter-atomic exchange Jij=5.9 meV. In thermal equilibrium, the combination of inter- and intra-atomic exchange interactions mediates spin order in the 4f system via the delocalized 5d valence bands...

    Read More

    Inspired by Art, Lightweight Solar Cells track the Sun

    September 9, 2015, Categories  Environment/Geology, Physics, Technology/Electronics

    Optical coupling efficiency and novel kirigami trackers.

    (a) Coupling efficiency (ηC) versus source angle (φ) for a planar solar panel. The panel projected area decreases with the cosφ. (b) A kirigami tracking structure that, upon stretching, simultaneously changes the angle of the elements comprising the sheet. By incorporating thin-film solar cells into this structure, it may be used as a low-profile alternative to conventional single-axis solar tracking. (c) The direction of feature tilt (that is, clockwise or counter-clockwise with respect to the original plane) is controlled by lifting or lowering one end of the sheet (step 1) before the straining process (step 2).

    Solar cells capture up to 40% more energy when they can track the sun, but conventional, motorized trackers are too heavy and bulky for pitched rooftops and vehicle surfaces...

    Read More

    Physicists Catch a Magnetic Wave that offers Promise for more Energy-Efficient Computing

    September 9, 2015, Categories  Physics, Technology/Electronics

     

    A team of physicists has taken pictures of a theorized but previously undetected magnetic wave, which offers the potential to be an energy-efficient means to transfer data in electronics. “This is an exciting discovery because it shows that small magnetic waves–known as spin-waves–can add up to a large one in a magnet, a wave that can maintain its shape as it moves,” explains NYU Prof Andrew Kent. “A specialized x-ray method that can focus on particular magnetic elements with very high spatial resolution enabled this discovery and should enable many more insights into this behavior.”

    To push the limits of energy efficiency in the future we need to understand better how magnetic devices behave on fast timescales at the nanoscale, which is why we are using this dedicated ultrafast x-ra...

    Read More