Scientists at Tokyo Institute of Technology produced subnano-sized metallic particles that are as much as 50 times more effective than well-known Au-Pd bimetallic nanocatalysts.
Category: particle physics – Page 578
Spacecraft Witness Explosion in Earth’s Magnetic Field
Magnetic fields around the Earth release strong bursts of energy, accelerating particles and feeding the auroras that glow in the polar skies. On July 11, 2017, four NASA spacecrafts were there to watch one of these explosions happen.
The process that produces these bursts is called magnetic reconnection, in which different plasmas and their associated magnetic fields interact, releasing energy. The Magnetospehric Multiscale Mission (MMS) satellites launched in 2015 to study the places where this reconnection process occurs. This newly released research shows for the first time that the mission encountered one of these reconnection sites in the night side of the Earth’s magnetic field, which extends behind the planet as a long “magnetotail.”
A two-atom quantum duet
Researchers at the Center for Quantum Nanoscience (QNS) within the Institute for Basic Science (IBS) achieved a major breakthrough in shielding the quantum properties of single atoms on a surface. The scientists used the magnetism of single atoms, known as spin, as a basic building block for quantum information processing. The researchers could show that by packing two atoms closely together they could protect their fragile quantum properties much better than for just one atom.
The spin is a fundamental quantum mechanical object and governs magnetic properties of materials. In a classical picture, the spin often can be considered like the needle of a compass. The north or south poles of the needle, for example, can represent spin up or down. However, according to the laws of quantum mechanics, the spin can also point in both directions at the same time. This superposition state is very fragile since the interaction of the spin with the local environment causes dephasing of the superposition. Understanding the dephasing mechanism and enhancing the quantum coherence are one of the key ingredients toward spin-based quantum information processing.
In this study, published in the journal Science Advances in November 9, 2018, QNS scientists tried to suppress the decoherence of single atoms by assembling them closely together. The spins, for which they used single titanium atoms, were studied by using a sharp metal tip of a scanning tunneling microscope and the atoms’ spin states were detected using electron spin resonance. The researchers found that by bringing the atoms very close together (1 million times closer than a millimeter), they could protect the superposition states of these two magnetically coupled atoms 20 times longer compared to an individual atom.
This mystery particle would need physics so weird nobody has even thought of it
Now scientists at the Large Hadron Collider (LHC) at Cern think they may have seen another particle, detected as a peak at a certain energy in the data, although the finding is yet to be confirmed. Again there’s a lot of excitement among particle physicists, but this time it is mixed with a sense of anxiety. Unlike the Higgs particle, which confirmed our understanding of physical reality, this new particle seems to threaten it.
The new result – consisting of a mysterious bump in the data at 28 GeV (a unit of energy) – has been published as a preprint on ArXiv. It is not yet in a peer-reviewed journal – but that’s not a big issue. The LHC collaborations have very tight internal review procedures, and we can be confident that the authors have done the sums correctly when they report a “4.2 standard deviation significance”. That means that the probability of getting a peak this big by chance – created by random noise in the data rather than a real particle – is only 0.0013%. That’s tiny – 13 in a million. So it seems like it must a real event rather than random noise – but nobody’s opening the champagne yet.
Earth Is Getting Hit by Too Much Antimatter, and Nobody Knows Why
Amid the high speed cosmic rays raining down on us from the depths of space are a handful of antimatter particles called positrons.
Astronomers think that Earth is showered by these ‘anti-electrons’ because of pulsars, but there’s a weird catch – there are more of these particles coming at us than there should be. And now, thanks to a new study, we might finally get some answers.
Cosmic rays are incredibly fast particles, since they’re being shot down from space at high energies. Positrons make up a small percent of these super speedy particles, but nobody is entirely sure where or how they’re made.
Quantum systems: Same, but different
Remarkable rules have been detected in the apparent chaos of disequilibrium processes. Different systems behave identically in many ways, if they belong to the same “universality class.” This means that experiments can be carried out with quantum systems that are easy to handle in order to obtain precise information about systems that cannot be directly studied in the experiment—such as the Big Bang.
Some phenomena are so complicated that it is impossible to precisely calculate them. This includes large quantum systems, which consist of many particles, particularly when they are not in an equilibrium state, but changing rapidly. Such examples include the wild particle inferno that occurs in particle accelerators when large atoms collide, or conditions just after the Big Bang, when particles rapidly expanded and then cooled.
At TU Wien and Heidelberg University, remarkable rules have been detected in the apparent chaos of disequilibrium processes. This indicates that such processes can be divided into universality classes. Systems belonging to the same class behave identically in many ways. This means that experiments can be carried out with quantum systems that are easy to handle in order to obtain precise information about other systems that cannot be directly studied in the experiment. These findings have since been published in the journal Nature.
At Last, Physicists Understand Where Matter’s Mass Comes From
Lattice QCD is not only teaching us how the strong interactions lead to the overwhelming majority of the mass of normal matter in our Universe, but holds the potential to teach us about all sorts of other phenomena, from nuclear reactions to dark matter.
Later today, November 7th, physics professor Phiala Shanahan will be delivering a public lecture from Perimeter Institute, and we&s;ll be live-blogging it right here at 7 PM ET / 4 PM PT. You can watch the talk right here, and follow along with my commentary below. Shanahan is an expert in theoretical nuclear and particle physics and specializes in supercomputer work involving QCD, and I&s;m so curious what else she has to say.
Airglow in Earth’s upper atmosphere shines in red, green, purple and yellow in this view from the International Space Station
Turbulence in this sea of charged particles can interfere with satellites 🛰 as well as communication 📡 and navigation 📶 signals. When it launches tomorrow, our #NASAICON mission will watch and image airglow, helping scientists better understand the extreme variability of the region where Earth meets space.