Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 145

In a new breakthrough, researchers have used a novel technique to confirm a previously undetected physics phenomenon that could be used to improve data storage in the next generation of computer devices.

Spintronic memories, utilized in advanced computers and satellites, leverage the magnetic states produced by the intrinsic angular momentum of electrons for data storage and retrieval. Depending on its physical motion, an electron’s spin produces a magnetic current. Known as the “spin Hall effect,” this has key applications for magnetic materials across many different fields, ranging from low-power electronics to fundamental quantum mechanics.

More recently, scientists have found that electrons are also capable of generating electricity through a second kind of movement: orbital angular momentum, similar to how Earth revolves around the sun. This is known as the “orbital Hall effect,” said Roland Kawakami, co-author of the study and a professor in physics at The Ohio State University.

Read more | >

In quantum mechanics, particles can exist in multiple states at the same time, defying the logic of everyday experiences. This property, known as quantum superposition, is the basis for emerging quantum technologies that promise to transform computing, communication, and sensing. But quantum superpositions face a significant challenge: quantum decoherence. During this process, the delicate superposition of quantum states breaks down when interacting with its surrounding environment.

To unlock the power of chemistry to build complex molecular architectures for practical quantum applications, scientists need to understand and control so that they can design with specific quantum coherence properties. Doing so requires knowing how to rationally modify a molecule’s chemical structure to modulate or mitigate quantum decoherence.

To that end, scientists need to know the “spectral density,” the quantity that summarizes how fast the environment moves and how strongly it interacts with the quantum system.

Read more | >

Dark matter may be more vibrant than previously thought, UC Riverside study reports.

Thought to make up 85% of matter in the universe, dark matter is nonluminous and its nature is not well understood. While normal matter absorbs, reflects, and emits light, dark matter cannot be seen directly, making it harder to detect. A theory called “self-interacting dark matter,” or SIDM, proposes that dark matter particles self-interact through a dark force, strongly colliding with one another close to the center of a galaxy.

In work published in The Astrophysical Journal Letters, a research team led by Hai-Bo Yu, a professor of physics and astronomy at the University of California, Riverside, reports that SIDM simultaneously can explain two astrophysics puzzles in opposite extremes.

Read more | >

A pair of astrophysicists at Tianjin University, in China, has proposed ways that humans in the distant future might use black holes as an energy source. In their paper published in the journal Physical Review D, Zhan-Feng Mai and Run-Qiu Yang outline two possible scenarios in which energy could potentially be harvested from primordial black holes.

As scientists continue to look for ways to meet the energy needs of a growing global population, some have begun to look for options that may not have been considered in the past. In this new effort, the researchers consider the possibility of tapping as a way to power human needs of the future by turning them into batteries.

The first option suggests future astro-engineers could “charge” a primordial black hole (a very small black hole with no spin that formed soon after the Big Bang) by feeding it electrically charged particles until the black hole begins to repel them, signaling it is fully charged, like a battery. Energy could then be collected from the black hole through the use of superradiance, whereby some of the electromagnetic or carrying more energy than was fed in are deflected into the black hole, captured first and converted into a usable energy source.

Read more | >

Kaiserslautern physicists in the team of Professor Dr. Herwig Ott have succeeded for the first time in directly observing pure trilobite Rydberg molecules. Particularly interesting is that these molecules have a very peculiar shape, which is reminiscent of trilobite fossils. They also have the largest electric dipole moments of any molecule known so far.

The researchers used a dedicated apparatus that is capable of preparing these fragile at ultralow temperatures. The results reveal their chemical binding mechanisms, which are distinct from all other chemical bonds. The study was published in the journal Nature Communications.

For their experiment, the physicists used a cloud of rubidium that was cooled down in an to about 100 microkelvin—0.0001 degrees above absolute zero. Subsequently, they excited some of these atoms into a so-called Rydberg state using lasers. “In this process, the outermost electron in each case is brought into far-away orbits around the atomic body,” explains Professor Herwig Ott, who researches ultracold quantum gases and quantum atom optics at University of Kaiserslautern-Landau.

Read more | >

Causality is key to our experience of reality: dropping a glass, for example, causes it to smash, so it can’t smash before it’s dropped. But in the quantum world those rules don’t necessarily apply, and scientists have now demonstrated how that weirdness can be harnessed to charge a quantum battery.

In a sense, you could say that quantum batteries are powered by paradoxes. On paper, they work by storing energy in the quantum states of atoms and molecules – but of course, as soon as the word “quantum” enters the conversation you know weird stuff is about to happen. In this case, a new study has found that quantum batteries could work by violating cause-and-effect as we know it.

“Current batteries for low-power devices, such as smartphones or sensors, typically use chemicals such as lithium to store charge, whereas a quantum battery uses microscopic particles like arrays of atoms,” said Yuanbo Chen, an author of the study. “While chemical batteries are governed by classical laws of physics, microscopic particles are quantum in nature, so we have a chance to explore ways of using them that bend or even break our intuitive notions of what takes place at small scales. I’m particularly interested in the way quantum particles can work to violate one of our most fundamental experiences, that of time.”

Read more | >

Quantum entanglement is the most distinctive signature of quantum mechanics, says Juan R. Muñoz de Nova, a condensed-matter physicist at the Complutense University of Madrid. “It contradicts the intuitions we have on a daily basis,” he says. “That is why entanglement is so intrinsic to quantum mechanics.”

This phenomenon has been observed by researchers around the world, and the 2022 Nobel Prize in physics was awarded to three scientists for experimentally advancing our understanding of it. Scientists have detected quantum entanglement through experiments involving macroscopic diamonds and ultracold gases.

In September 2023, the ATLAS collaboration made another advancement when they unveiled the highest-energy measurement of quantum entanglement ever, using top quarks produced in the Large Hadron Collider at CERN. Interestingly, the measurement turned out a bit differently than expected.

Read more | >

Researchers in China have produced a phenomenon known as the giant skyrmion topological Hall effect in a two-dimensional material using only a small amount of current to manipulate the skyrmions responsible for it. The finding, which a team at Huazhong University of Science and Technology in Hubei observed in a ferromagnetic crystal discovered in 2022, comes about thanks to an electronic spin interaction known to stabilize skyrmions. Since the effect was apparent at a wide range of temperatures, including room temperature, it could prove useful for developing two-dimensional topological and spintronic devices such as racetrack memory, logic gates and spin nano-oscillators.

Skyrmions are quasiparticles with a vortex-like structure, and they exist in many materials, notably magnetic thin films and multilayers. They are robust to external perturbations, and at just tens of nanometres across, they are much smaller than the magnetic domains used to encode data in today’s hard disks. That makes them ideal building blocks for future data storage technologies such as “racetrack” memories.

Skyrmions can generally be identified in a material by spotting unusual features (for example, abnormal resistivity) in the Hall effect, which occurs when electrons flow through a conductor in the presence of an applied magnetic field. The magnetic field exerts a sideways force on the electrons, leading to a voltage difference in the conductor that is proportional to the strength of the field. If the conductor has an internal magnetic field or magnetic spin texture, like a skyrmion does, this also affects the electrons. In these circumstances, the Hall effect is known as the skyrmion topological Hall effect (THE).

Read more | >

Materials with enhanced thermal conductivity are critical for the development of advanced devices to support applications in communications, clean energy and aerospace. But in order to engineer materials with this property, scientists need to understand how phonons, or quantum units of the vibration of atoms, behave in a particular substance.

“Phonons are quite important for studying new because they govern several such as thermal conductivity and carrier properties,” said Fuyang Tay, a graduate student in applied physics working with the Rice Advanced Magnet with Broadband Optics (RAMBO), a tabletop spectrometer in Junichiro Kono’s laboratory at Rice University. “For example, it is widely accepted that superconductivity arises from electron–phonon interactions.

Recently, there has been growing interest in the carried by phonon modes that show circular motion, also known as chiral . But the mechanisms that can lead to a large phonon magnetic moment are not well understood.

Read more | >

Virtual reality, or VR, is not just for fun-filled video games and other visual entertainment. This technology, involving a computer-generated environment with objects that seem real, has found many scientific and educational applications as well.

Sean Preins, a doctoral student in the Department of Physics and Astronomy at the University of California, Riverside, has created a VR application called VIRTUE, for “Virtual Interactive Reality Toolkit for Understanding the EIC,” that is a game changer in how particle and nuclear physics data can be seen.

Made publicly available on Christmas Day, VIRTUE can be used to visualize experiments and simulated data from the upcoming Electron-Ion Collider, or EIC, a planned major new nuclear physics research facility at Brookhaven National Lab in Upton, New York. EIC will explore mysteries of the “strong force” that binds the atomic nucleus together. Electrons and ions, sped up to almost the speed of light, will collide with one another in the EIC.

Read more | >