quantum tunneling tagged posts

Dark matter could make planets spin faster

artist_s_impression_of_how_the_very_early_universe_might_have_looked_pillars.jpg

Dark matter is a confounding concept that teeters on the leading edges of cosmology and physics. We don’t know what it is or how exactly it fits into our understanding of the universe. We only know that its unseen mass is a critical part of the cosmos.

Astronomers know dark matter exists. They can tell by the way galaxies rotate, by exploiting gravitational lensing, and by analyzing fluctuations in the Cosmic Microwave Background. But new research suggests that there might be another way to detect its presence.

The research is “Dark Matter (S)pins the Planet,” and it’s available on the arXiv preprint server. Haihao Shi, from the Xinjiang Astronomical Observatory at the Chinese Academy of Sciences, is the lead author. The co-authors are all from Chinese research institutions.

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A Quantum Neural Network can see Optical Illusions Like Humans do. Could it be the Future of AI?

A quantum neural network can see optical illusions like humans do. Could it be the future of AI?
(a) Sketch of the QT-DNN structure. W(n) with n = 1 … 4 are the matrices of the weights of the network connections. (b) QT-DNN model employs the physical effect of QT as the activation function of its nodes. (b.i) One-dimensional rectangular potential barrier of thickness a and height V0. (b.ii) Unlike in classical mechanics, in quantum mechanics, there is a non-zero probability for an electron with energy E < V0 to be transmitted through the barrier. Credit: APL Machine Learning (2024). DOI: 10.1063/5.0225771

Optical illusions, quantum mechanics and neural networks might seem to be quite unrelated topics at first glance...

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The Iron Stepping Stones to Better Wearable Tech without Semiconductors

Iron-dotted boron nitride nanotubes, made in Yoke Khin Yaps' lab at Michigan Tech, could make for better wearable tech because of their flexibility and electronic behaviors. Credit: Michigan Tech, Sue Hill

Iron-dotted boron nitride nanotubes, made in Yoke Khin Yaps’ lab at Michigan Tech, could make for better wearable tech because of their flexibility and electronic behaviors. Credit: Michigan Tech, Sue Hill

The road to more versatile wearable technology is dotted with iron. Specifically, quantum dots of iron arranged on boron nitride nanotubes (BNNTs). Yap says the iron-studded BNNTs are pushing the boundaries of electronics hardware. The transistors modulating electron flow need an upgrade.

“Look beyond semiconductors,” he says, explaining that materials like silicon semiconductors tend to overheat, can only get so small and leak electric current. The key to revamping the fundamental base of transistors is creating a series of stepping-stones that use quantum tunneling.

The nanotubes are t...

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Researchers create World’s Highest-Performance Single-Molecule Diode

Major milestone in molecular electronics. Berkeley Lab and Columbia Uni team used a combination of gold electrodes and an ionic solution to create a single-molecule diode that outperforms the best of its predecessors by a factor of 50.

“Using a single symmetric molecule, an ionic solution and two gold electrodes of dramatically different exposed surface areas, we were able to create a diode that resulted in a rectification ratio, the ratio of forward to reverse current at fixed voltage, in excess of 200, which is a record for single-molecule devices,” says Jeff Neaton, Director of the Molecular Foundry. “The asymmetry necessary for diode behavior originates with the different exposed electrode areas and the ionic solution,” he says...

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