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Framework sets new benchmarks for 3D atom maps in amorphous materials

Researchers at the California NanoSystems Institute at UCLA published a step-by-step framework for determining the three-dimensional positions and elemental identities of atoms in amorphous materials. These solids, such as glass, lack the repeating atomic patterns seen in a crystal. The team analyzed realistically simulated electron-microscope data and tested how each step affected accuracy.

The team used algorithms to analyze rigorously simulated imaging data of nanoparticles—so small they’re measured in billionths of a meter. For amorphous silica, the primary component of glass, they demonstrated 100% accuracy in mapping the three-dimensional positions of the constituent silicon and oxygen atoms, with precision about seven trillionths of a meter under favorable imaging conditions.

While 3D atomic structure determination has a history of more than a century, its application has been limited to crystal structures. Such techniques depend on averaging a pattern that is repeated trillions of times.

The infant universe’s ‘primordial soup’ was actually soupy, study finds

In its first moments, the infant universe was a trillion-degree-hot soup of quarks and gluons. These elementary particles zinged around at light speed, creating a “quark-gluon plasma” that lasted for only a few millionths of a second. The primordial goo then quickly cooled, and its individual quarks and gluons fused to form the protons, neutrons, and other fundamental particles that exist today.

Physicists at CERN’s Large Hadron Collider in Switzerland are recreating quark-gluon plasma (QGP) to better understand the universe’s starting ingredients. By smashing together heavy ions at close to light speeds, scientists can briefly dislodge quarks and gluons to create and study the same material that existed during the first microseconds of the early universe.

Now, a team at CERN led by MIT physicists has observed clear signs that quarks create wakes as they speed through the plasma, similar to a duck trailing ripples through water. The findings are the first direct evidence that quark-gluon plasma reacts to speeding particles as a single fluid, sloshing and splashing in response, rather than scattering randomly like individual particles.

Quantum batteries could quadruple qubit capacity while reducing energy infrastructure requirements

Scientists have unveiled a new approach to powering quantum computers using quantum batteries—a breakthrough that could make future computers faster, more reliable, and more energy efficient.

Quantum computers rely on the rules of quantum physics to solve problems that could transform computing, medicine, energy, finance, communications, and many other fields in the years ahead.

But sustaining their delicate quantum states typically requires room-sized, energy-intensive cryogenic cooling systems, as well as a system of room-temperature electronics.

The first direct observation of a liquid charge density wave

Charge density waves (CDWs) are ordered, crystal-like patterns in the arrangement of electrons that spontaneously form inside some solid materials. These patterns can change how electricity flows through materials, in some cases prompting the emergence of superconductivity or other unusual physical states.

Physics theories suggest that at certain temperatures CDWs “melt,” similarly to how conventional solids transition to a liquid state. So far, however, this transition to a liquid CDW had not yet been observed experimentally.

Researchers at University of California Los Angeles (UCLA) have gathered the first direct evidence of a CDW liquid state in the layered transition metal dichalcogenide 1T-TaS2. Their paper, published in Nature Physics, could open new possibilities for the study of hidden electronic phases in correlated physical systems.

Novel ‘XFELO’ laser system produces razor-sharp X-ray light

A team of engineers and scientists has shown for the first time that a hard-X-ray cavity can provide net X-ray gain, with X-ray pulses being circulated between crystal mirrors and amplified in the process, much like happens with an optical laser. The result of the proof-of-concept at European XFEL is a particularly coherent, laser-like light of a quality that is unprecedented in the hard X-ray spectrum.

Lasing inside a cavity had been challenging to achieve with short-wavelength X-rays for a variety of reasons, including—on a basic level—that the nature of the light makes it difficult to reflect the beam at large angles. The “XFELO” (short for: X-Ray Free-Electron Laser Oscillator) technique opens new perspectives for scientific investigations, from ultrafast chemical reactions to detailed analyses of the smallest biological structures. The research is published in the journal Nature.

Chip-sized optical amplifier can intensify light 100-fold with minimal energy

Light does a lot of work in the modern world, enabling all types of information technology, from TVs to satellites to fiber-optic cables that carry the internet across oceans. Stanford physicists recently found a way to make that light work even harder with an optical amplifier that requires low amounts of energy without any loss of bandwidth, all on a device the size of a fingertip.

Similar to sound amplifiers, optical amplifiers take a light signal and intensify it. Current small-sized optical amplifiers need a lot of power to function. The new optical amplifier, detailed in the journal Nature, solves this problem by using a method that essentially recycles the energy used to power it.

“We’ve demonstrated, for the first time, a truly versatile, low-power optical amplifier, one that can operate across the optical spectrum and is efficient enough that it can be integrated on a chip,” said Amir Safavi-Naeini, the study’s senior author and associate professor of physics in Stanford’s School of Humanities and Sciences. “That means we can now build much more complex optical systems than were possible before.”

New light-based platform sets the stage for future quantum supercomputers

A light has emerged at the end of the tunnel in the long pursuit of developing quantum computers, which are expected to radically reduce the time needed to perform some complex calculations from thousands of years down to a matter of hours.

A team led by Stanford physicists has developed a new type of “optical cavity” that can efficiently collect single photons, the fundamental particle of light, from single atoms. These atoms act as the building blocks of a quantum computer by storing “qubits”—the quantum version of a normal computer’s bits of zeros and ones. This work enables that process for all qubits simultaneously, for the first time.

In a study published in Nature, the researchers describe an array of 40 cavities containing 40 individual atom qubits as well as a prototype with more than 500 cavities. The findings indicate a way to ultimately create a million-qubit quantum computer network.

New ABF crystal delivers high-performance vacuum ultraviolet nonlinear optical conversion

Vacuum ultraviolet (VUV, 100–200 nm) light sources are indispensable for advanced spectroscopy, quantum research, and semiconductor lithography. Although second harmonic generation (SHG) using nonlinear optical (NLO) crystals is one of the simplest and most efficient methods for generating VUV light, the scarcity of suitable NLO crystals has long been a bottleneck.

To address this problem, a research team led by Prof. Pan Shilie at the Xinjiang Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences (CAS) has developed the fluorooxoborate crystal NH4B4O6F (ABF)—offering an effective solution to the practical challenges of VUV NLO materials. The team’s findings were recently published in Nature.

The team’s key achievement is the development of centimeter-scale, high-quality ABF crystal growth and advanced anisotropic crystal processing technologies. Notably, ABF uniquely integrates a set of conflicting yet critical properties required for VUV NLO materials—excellent VUV transparency, a strong NLO coefficient, and substantial birefringence for VUV phase-matching—while fulfilling stringent practical criteria: large crystal size for fabricating devices with specific phase-matching angles, stable physical/chemical properties, a high laser-induced damage threshold, and suitable processability. This breakthrough resolves the long-standing field challenge where no prior crystal has met all these criteria simultaneously.

Laser beam flips a ferromagnet’s polarity without heating the material

Researchers at the University of Basel and the ETH in Zurich have succeeded in changing the polarity of a special ferromagnet using a laser beam. In the future, this method could be used to create adaptable electronic circuits with light.

In a ferromagnet, combined forces are at work. In order for a compass needle to point north or a fridge magnet to stick to the fridge door, countless electrons spin inside them, each of which only creates a tiny magnetic field, all need to line up in the same direction. This happens through interactions between the spins, which have to be stronger than the disordered thermal motion inside the ferromagnet. If the temperature of the material is below a critical value, it becomes ferromagnetic.

Conversely, to change the polarity of a ferromagnet, one usually needs to first heat it up above its critical temperature. The electron spins can then reorient themselves, and after cooling down, the magnetic field of the ferromagnet eventually points in a different direction.

Establishing design principles for achieving ultralow thermal conductivity via controlled chemical disorder

A major challenge in thermal-management and thermal-insulation technologies, across multiple industries, is the lack of materials that simultaneously offer low thermal conductivity, mechanical robustness, and scalable fabrication routes.

Discovering materials that exhibit completely insulating thermal behavior—or, conversely, extraordinarily high thermal conductivity—has long been a dream for researchers in materials physics. Traditionally, amorphous materials are known to possess very low thermal conductivity.

This naturally leads to an important question: Can a crystalline material be engineered to achieve thermal conductivity close to that of an amorphous solid? Such a material would preserve the structural stability of a crystal while achieving exceptionally low thermal conductivity.

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