Portable optical atomic clock makes its commercial debut

12 Dec 2023

Simple setup: The iodine vapour cells used in Vector Atomic's portable optical atomic clock. (Courtesy: Vector Atomic)

Atoms are the world’s most precise timekeepers – so much so that the second is defined as exactly 9 192 631 770 ticks of a caesium-based atomic clock. Commercially-available versions of these atomically precise clocks underpin GPS, navigation, data transfer and financial markets, and they run at microwave frequencies, or billions of tick-tocks per second. After a day, their timekeeping is out by less than ten nanoseconds.

 

Quantum simulator visualizes large-scale entanglement in materials

14 Dec 2023

How entangled is it? The researchers obtained temperature profiles of their system showing that particles that interact strongly are “hot” (red) and those that interact little are “cold” (blue). Entanglement is greatest when interactions are strong. (Courtesy: Helene Hainzer)

Physicists in Austria have found a quick and efficient way of extracting information on a quantum material’s large-scale entanglement structure thanks to a 50-year-old theorem from quantum field theory. The new method could open doors in fields such as quantum information, quantum chemistry or even high-energy physics.

 

Charge qubits get a thousand-fold boost

04 Dec 2023

Keeping quantum: Artist's rendering of two charge qubits with a long coherence time and strong coupling. (Courtesy: Dafei Jin/Argonne National Laboratory and the University of Notre Dame)

Researchers in the US have improved the coherence time of charge quantum bits (qubits) by a factor of 1000 thanks to advances in the materials used to construct them. Led by Dafei Jin of the Argonne Center for Nanoscale Materials and David Schuster of Stanford University and the University of Chicago, the multi-institutional team also showed it was possible to read out the state of these qubits with a fidelity of 98.1% – a value Jin says will increase further with the aid of more sophisticated readout technologies.

 

What volcanoes and coffeemaking have in common, the physics of playing the didjeridu

08 Dec 2023 Hamish Johnston

Espresso eruption: static electricity affects your cup of coffee. (Courtesy: iStock/radu984)

What do volcanic eruptions and grinding coffee have in common? According to a team of coffee chemists and geophysicists in the US and the Republic of Korea, they both produce a fair amount of static electricity, so much so that volcanologists are now examining the espresso-making process.

It is well-known that static electricity is created when grinding coffee beans due to the fracturing and friction that occurs. This causes coffee particles to clump together and stick to the grinder. However, not much was known about how this impacts the resulting brewed coffee.

 

Resonant excitation of nuclear clock transition spotted at XFEL

17 Oct 2023

Nuclear timekeeper Illustration of a scandium nucleus with a superimposed clock. (Courtesy: European XFEL/Helmholtz Institute Jena/Tobias Wüstefeld/Ralf Röhlsberger)

An important step towards creating an extremely accurate clock based on a nuclear transition has been taken by an international team of physicists. Yuri Shvyd’ko at Argonne National Laboratory in the US and colleagues have achieved the resonant excitation of a nuclear transition in scandium-45. The transition could be used to create a nuclear clock with the potential to be much more accurate that the best atomic clocks available today.

 

Scandium breaks temperature record for elemental superconductors

07 Dec 2023 Isabelle Dumé

Scandium is the only known elemental superconductor to have a critical temperature in the 30 K range. This phase diagram shows the superconducting transition temperature (Tc) and crystal structure versus pressure for scandium. The measured results on all the five samples studied show consistent trends. (Courtesy: Chinese Phys. Lett. 40 107403)

Scandium remains a superconductor at temperatures above 30 K, making it the first element known to superconduct at such a high temperature. The record-breaking discovery was made by researchers in China, Japan and Canada who subjected the element to pressures of up to 283 GPa – around 2.3 million times atmospheric pressure at sea level.

 

Simultaneous production of a top quark and a photon was observed for the first time

04 Dec 2023

Observational first: physicists have used the ATLAS experiment at CERN to observe the production of top-quark and photon pairs. (Courtesy: CERN)

For the first time, particle physicists have observed the simultaneous production of a photon and a top quark. The milestone was achieved by the ATLAS collaboration, which operates a giant detector at CERN’s Large Hadron Collider (LHC). The discovery could lead to a deeper understanding of the electroweak interaction, and its enigmatic relationship with the Higgs field.

 

Bound antimatter ejects molecular ions from crystals

10 Nov 2023

Antimatter lab: the slow positron beam apparatus used by the Tokyo researchers. (Courtesy: Yasuyuki Nagashima/Tokyo University of Science)

Strong evidence that positrons can exist in short-lived bound states within solid matter has been found by researchers in Japan. By analysing experiments using new theoretical models, Takayuki Tachibana and colleagues at the Tokyo University of Science showed how the exotic states are involved in the emission of molecular ions from ionic crystals that are being bombarded with low-energy positron beams.

 

A surprising link discovered between fast radio bursts and earthquakes

21 Oct 2023

Common trends: researchers at the University of Tokyo have used data taken by telescopes such as the Arecibo observatory in Puerto Rico (pictured here in 2019) to uncover similarities between fast radio bursts and earthquakes (Courtesy: UCF)

Researchers in Japan have found striking similarities between the statistical behaviour of repeating fast radio bursts (FRBs) and earthquakes.

FRBs are brief, intense bursts of radio waves from outside our galaxy. Whilst these bursts typically last a few milliseconds, astronomers have also found bursts a thousand times shorter.

 

Mysterious ultrahigh-energy cosmic ray puzzles astronomers

27 Nov 2023

Sun goddess: illustration of the shower of particles created by Amaterasu as it entered the atmosphere above the Telescope Array in Utah. (Courtesy: Osaka Metropolitan University/L-INSIGHT, Kyoto University/Ryuunosuke Takeshige)

A cosmic-ray particle with an energy about 36 million times greater than the particles accelerated by CERN’s Large Hadron Collider has been detected. At 244 EeV, this is one of the most energetic particles ever observed and was spotted in 2021 by the Telescope Array in Utah. While the ultrahigh-energy cosmic ray (UHECR) was probably created by a violent astrophysical process, researchers were unable to trace it back to its origins.

 

Lots of oxygen existed in the early universe, JWST reveals

06 Dec 2023

Cutting edge: NIRSpec being readied for the launch of the JWST. (Courtesy: Astrium/NIRSpec)

Using a cutting-edge spectrograph on the James Webb Space Telescope (JWST), astronomers have found evidence that interstellar oxygen was far more abundant in many ancient galaxies than previously thought. Led by Kimihiko Nakajima at the National Astronomical Observatory of Japan, the team hopes that their observations could improve our understanding of the early universe.

 

Ion-exchange bead writes underwater

09 Oct 2023 Isabelle Dumé

Water writing: As the bead moves, it trades residual cations in the water for protons, and thus traces out an invisible track of lower pH in the liquid. Linear scales: 250 µm. (Courtesy: ill./©: Thomas Palberg, Benno Liebchen)

Writing requires a substrate, like clay or paper, to fix the written lines and letters in place. Doing the same thing in a liquid such as water is not possible because the movement of the pen creates turbulence that quickly eradicates ink trails. In principle, you could remove this turbulence by using a very tiny pen, since smaller moving objects create fewer vortices, but even a tiny pen would require a substantial reservoir of ink, cancelling out any size advantage.

 

The planet system is perfectly tuned

01 Dec 2023

Planetary harmony: illustration of the orbits of the six exoplanets of HD 110067. (Courtesy:Medienmitteilung/UniBE/UniGE/CHEOPS/TESS/Sextett/Planete/Walzer/Video©UniBE/HughOsborn)

A rare system of six exoplanets, all smaller than Neptune but larger than Earth, has been found with orbits that are all resonant with each other. The system was discovered by astronomers led by Rafael Luque of the University of Chicago, who suggest that the planets have remained undisturbed in this configuration since their formation a billion years ago.

The planetary treasure trove also provides one of the best opportunities for characterizing “mini-Neptunes”, which are a mysterious class of planet that are absent from the Solar System.

 

Terahertz laser induces a room-temperature superconducting phase in a fullerene compound

30 Nov 2023 Isabelle Dumé

The optical setup used to generate the low frequency laser pulses that resonantly excited the sample. Courtesy: J. Witt, MPSD

An organic material in a metastable phase behaves a little like a room-temperature superconductor when excited with laser light. Though this behaviour fades almost as quickly as the laser pulse that induces it, the team behind the discovery say that with the right light source, it might be possible to keep the material in its superconducting-like state continuously.

Scientists have known for a while that shining light at terahertz and mid-infrared frequencies on certain materials is a good way to manipulate their properties. In some cases, this method can even be used to create non-equilibrium material phases that have no analogue under normal conditions.

 

Demon quasiparticle is detected 67 years after it was first proposed

04 Sep 2023

Lurking for decades: researchers have discovered Pines' demon, a collection of electrons in a metal that behaves like a massless wave. It is illustrated here as an artist’s impression. (Courtesy: The Grainger College of Engineering/University of Illinois Urbana-Champaign)

For nearly seven decades, a plasmon known as Pines’ demon has remained a purely hypothetical feature of solid-state systems. Massless, neutral and unable to interact with light, this unusual quasiparticle is reckoned to play a key role in certain superconductors and semimetals. Now scientists in the US and Japan say they have finally detected it while using specialized electron spectroscopy to study the material strontium ruthenate.