Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics

Finding the hypothetical particle axion could mean finding out for the first time what happened in the Universe a second after the Big Bang, suggests a new study published in Physical Review D.

How far back into the Universe’s past can we look today? In the electromagnetic spectrum, observations of the Cosmic Microwave Background — commonly referred to as the CMB — allow us to see back almost 14 billion years to when the Universe cooled sufficiently for protons and electrons to combine and form neutral hydrogen. The CMB has taught us an inordinate amount about the evolution of the cosmos, but photons in the CMB were released 400000 years after the Big Bang making it extremely challenging to learn about the history of the universe prior to this epoch.

To open a new window, a trio of theoretical researchers, including Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Principal Investigator, University of California, Berkeley, MacAdams Professor of Physics and Lawrence Berkeley National Laboratory senior faculty scientist Hitoshi Murayama, Lawrence Berkeley National Laboratory physics researcher and University of California, Berkeley, postdoctoral fellow Jeff Dror (now at University of California, Santa Cruz), and UC Berkeley Miller Research Fellow Nicholas Rodd, looked beyond photons, and into the realm of hypothetical particles known as axions, which may have been emitted in the first second of the Universe’s history.

Read more | >

The scientists studied fermion masses which they are of the belief that can be communicated into the fifth dimension through portals, forming dark matter relics and ‘fermionic dark matter’ within the novel fifth dimension.

Researchers said in a statement to Vice, “We found that the new scalar field had an interesting, non-trivial behaviour along the extra dimension. If this heavy particle exists, it would necessarily connect the visible matter that we know and that we have studied in detail with the constituents of dark matter, assuming the dark matter is composed out of fundamental fermions, which live in the extra dimension.”

They refer to the particle as a potential messenger to the dark sector. But hypothesising is not as hard as actually looking for the particle. If you didn’t know, the Higgs Boson Particle which was discovered in 2012 and also rewarded the discoverer with a Nobel Prize, was first proposed sometime in 1964. It was only discovered after the construction of the Large Hadron Collider — world’s most powerful particle accelerator.

Read more | >

Physics-informed machine learning might help verify microchips.

Physicists love recreating the world in software. A simulation lets you explore many versions of reality to find patterns or to test possibilities. But if you want one that’s realistic down to individual atoms and electrons, you run out of computing juice pretty quickly.

Machine-learning models can approximate detailed simulations, but often require lots of expensive training data. A new method shows that physicists can lend their expertise to machine-learning algorithms, helping them train on a few small simulations consisting of a few atoms, then predict the behavior of system with hundreds of atoms. In the future, similar techniques might even characterize microchips with billions of atoms, predicting failures before they occur.

The researchers started with simulated units of 16 silicon and germanium atoms, two elements often used to make microchips. They employed high-performance computers to calculate the quantum-mechanical interactions between the atoms’ electrons. Given a certain arrangement of atoms, the simulation generated unit-level characteristics such as its energy bands, the energy levels available to its electrons. But “you realize that there is a big gap between the toy models that we can study using a first-principles approach and realistic structures,” says Sanghamitra Neogi, a physicist at the University of Colorado, Boulder, and the paper’s senior author. Could she and her co-author, Artem Pimachev, bridge the gap using machine learning?

Read more | >

Researchers at ETH Zurich have succeeded in observing a crystal that consists only of electrons. Such Wigner crystals were already predicted almost ninety years ago but could only now be observed directly in a semiconductor material.

Crystals have fascinated people through the ages. Who hasn’t admired the complex patterns of a snowflake at some point, or the perfectly symmetrical surfaces of a rock crystal? The magic doesn’t stop even if one knows that all this results from a simple interplay of attraction and repulsion between atoms and electrons. A team of researchers led by Ataç Imamoğlu, professor at the Institute for Quantum Electronics at ETH Zurich, have now produced a very special crystal. Unlike normal crystals, it consists exclusively of electrons. In doing so, they have confirmed a that was made almost ninety years ago and which has since been regarded as a kind of holy grail of condensed matter physics. Their results were recently published in the scientific journal Nature.

Read more | >

Researchers at ETH Zurich have succeeded in observing a crystal that consists only of electrons. Such Wigner crystals were already predicted almost ninety years ago but could only now be observed directly in a semiconductor material.

Crystals have fascinated people through the ages. Who hasn’t admired the complex patterns of a snowflake at some point, or the perfectly symmetrical surfaces of a rock crystal? The magic doesn’t stop even if one knows that all this results from a simple interplay of attraction and repulsion between atoms and electrons. A team of researchers led by Ataç Imamoğlu, professor at the Institute for Quantum Electronics at ETH Zurich, have now produced a very special crystal. Unlike normal crystals, it consists exclusively of electrons. In doing so, they have confirmed a theoretical prediction that was made almost ninety years ago and which has since been regarded as a kind of holy grail of condensed matter physics. Their results were recently published in the scientific journal Nature.

A decades-old prediction

“What got us excited about this problem is its simplicity,” says Imamoğlu. Already in 1934 Eugene Wigner, one of the founders of the theory of symmetries in quantum mechanics, showed that electrons in a material could theoretically arrange themselves in regular, crystal-like patterns because of their mutual electrical repulsion. The reasoning behind this is quite simple: if the energy of the electrical repulsion between the electrons is larger than their motional energy, they will arrange themselves in such a way that their total energy is as small as possible.

Read more | >

Technology advance could enable space-based atomic clocks, improving communications and GPS navigation.

Although quantum technology has proven valuable for highly precise timekeeping, making these technologies practical for use in a variety of environments is still a key challenge. In an important step toward portable quantum devices, researchers have developed a new high-flux and compact cold-atom source with low power consumption that can be a key component of many quantum technologies.

“The use of quantum technologies based on laser-cooled atoms has already led to the development of atomic clocks that are used for timekeeping on a national level,” said research team leader Christopher Foot from Oxford University in the U.K. “Precise clocks have many applications in the synchronization of electronic communications and navigation systems such as GPS. Compact atomic clocks that can be deployed more widely, including in space, provide resilience in communications networks because local clocks can maintain accurate timekeeping even if there is a network disruption.”

Read more | >

Researchers have created an unusual new alloy made up of not two, but five different metals, and put it to work as a catalyst. The new material is two-dimensional, and was able to convert carbon dioxide into carbon monoxide effectively, potentially helping to turn the greenhouse gas into fuels.

The new alloy belongs to a class of materials called transition metal dichalcogenides (TMDCs), which are, as the name suggests, made up of combinations of transition metals and chalcogens. Extremely thin films of TMDCs have recently shown promise in a range of electronic and optical devices, but researchers on the new study wondered if they could also be used as catalysts for chemical reactions.

The thinking goes that because reactions occur on the surface of a catalyst, materials with high surface areas will be more effective catalysts. And as sheets only a few atoms thick, TMDCs are almost nothing but surface area.

Read more | >

The Large Hadron Collider has a lot of tasks ahead of it. Next stop: investigating the Big Bang.

The truth is, we don’t really know because it takes huge amounts of energy and precision to recreate and understand the cosmos on such short timescales in the lab.

But scientists at the Large Hadron Collider (LHC) at CERN, Switzerland aren’t giving up.

Now our LHCb experiment has measured one of the smallest differences in mass between two particles ever, which will allow us to discover much more about our enigmatic cosmic origins.

Read more | >

Three years ago, Arthur Ashkin won the Nobel Prize for inventing optical tweezers, which use light in the form of a high-powered laser beam to capture and manipulate particles. Despite being created decades ago, optical tweezers still lead to major breakthroughs and are widely used today to study biological systems.

However, optical tweezers do have flaws. The prolonged interaction with the can alter molecules and particles or damage them with excessive heat.

Researchers at The University of Texas at Austin have created a new version of optical tweezer technology that fixes this problem, a development that could open the already highly regarded tools to new types of research and simplify processes for using them today.

Read more | >