Killer electrons in strumming northern and southern lights — ScienceDaily

Computer simulations explain how electrons with wide-ranging energies rain into Earth’s upper and middle atmosphere during a phenomenon known as the pulsating aurora. The findings, published in the journal Geophysical Research Letters, suggest that the higher-energy electrons resulting from this process could cause destruction of the part of the ozone in the mesosphere, about 60 kilometres above Earth’s surface. The study was a collaboration between scientists in Japan, including at Nagoya University, and colleagues in the US, including from NASA.

The northern and southern lights that people are typically aware of, called the aurora borealis and australis, look like coloured curtains of reds, greens, and purples spreading across the night skies. But there is another kind of aurora that is less frequently seen. The pulsating aurora looks more like indistinct wisps of cloud strumming across the sky.

Scientists have only recently developed the technologies enabling them to understand how

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Researchers create nanoscale slalom course for electrons

Pitt researchers create nanoscale slalom course for electrons
Illustration of sketched serpentine nanowires created from lanthanum aluminate and strontium titanate. The side-to-side motion of the electrons as they travel gives them additional properties that can be used to make quantum devices. Credit: Jeremy Levy

A research team led by professors from the Department of Physics and Astronomy have created a serpentine path for electrons, imbuing them with new properties that could be useful in future quantum devices.


Jeremy Levy, a distinguished professor of condensed matter physics, and Patrick Irvin, research professor, are coauthors of the paper “Engineered spin-orbit interactions in LaAlO3/SrTiO3-based 1D serpentine electron waveguides,” published in Science Advances on November 25.

“We already know how to shoot electrons ballistically through one-dimensional nanowires made from these oxide materials,” explains Levy. “What is different here is that we have changed the environment for the electrons, forcing them to weave left and right as they travel.

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‘New Kind of Electrons’ — ScienceDaily

It is something quite common in physics: electrons leave a certain material, they fly away and then they are measured. Some materials emit electrons, when they are irradiated with light. These electrons are then called “photoelectrons.” In materials research, so-called “Auger electrons” also play an important role — they can be emitted by atoms if an electron is first removed from one of the inner electron shells. But now scientists at TU Wien (Vienna) have succeeded in explaining a completely different type of electron emission, which can occur in carbon materials such as graphite. This electron emission had been known for about 50 years, but its cause was still unclear.

Strange electrons without explanation

“Many researchers have already wondered about this,” says Prof. Wolfgang Werner from the Institute of Applied Physics. “There are materials that consist of atomic layers that are held together only by weak Van der Waals forces,

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Researchers trap electrons to create elusive crystal

electron
Credit: Unsplash/CC0 Public Domain

Like restless children posing for a family portrait, electrons won’t hold still long enough to stay in any kind of fixed arrangement.


Cornell researchers stacked two-dimensional semiconductors to create a moiré superlattice structure that traps electrons in a repeating pattern, ultimately forming the long-hypothesized Wigner crystal.

Now, a Cornell-led collaboration has developed a way to stack two-dimensional semiconductors and trap electrons in a repeating pattern that forms a specific and long-hypothesized crystal.

The team’s paper, “Correlated Insulating States at Fractional Fillings of MoirĂ© Superlattices,” published Nov. 11 in Nature. The paper’s lead author is postdoctoral researcher Yang Xu.

The project grew out of the shared lab of Kin Fai Mak, associate professor of physics in the College of Arts and Sciences, and Jie Shan, professor of applied and engineering physics in the College of Engineering, the paper’s co-senior authors. Both researchers are members of the

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