Category Physics

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

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...

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Celeste: new Statistical Analysis Model designed to enhance astronomy’s most time-tested tools: Sky Surveys

Celeste

The Celeste graphical model. Shaded vertices represent observed random variables. Empty vertices represent latent ran- dom variables. Black dots represent constants. Constants denoted by uppercase Greek characters are fixed and denote parameters of prior distributions. The remaining constants and all latent random variables are inferred.

Berkeley Lab-based research collaboration of astrophysicists, statisticians and computer scientists is looking to shake things up with Celeste, a new statistical analysis model designed to enhance one of modern astronomy’s most time-tested tools: sky surveys...

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Inspired by Art, Lightweight Solar Cells track the Sun

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...

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

 

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...

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