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In-plane magnetic fields unveil novel Hall effect behaviors in advanced materials, transforming our understanding of electronic transport.

Researchers from the Institute of Science Tokyo have reported that in-plane magnetic fields induce an anomalous Hall effect in EuCd₂Sb₂ films. By investigating how these fields alter the electronic structure, the team uncovered a significant in-plane anomalous Hall effect. This discovery opens new avenues for controlling electronic transport in magnetic fields, with potential applications in magnetic sensors.

The Hall effect, a fundamental phenomenon in material science, occurs when a material carrying an electric current is subjected to a magnetic field, creating a voltage perpendicular to both the current and the field. While the Hall effect has been extensively studied in materials under out-of-plane magnetic fields, the effects of in-plane magnetic fields have received comparatively little attention.

“Genesis” can compress training times from decades into hours using 3D worlds conjured from text.

When Lawrence Livermore National Laboratory (LLNL) achieved fusion ignition at the National Ignition Facility (NIF) in December 2022, the world’s attention turned to the prospect of how that breakthrough experiment — designed to secure the nation’s nuclear weapons stockpile — might also pave the way for virtually limitless, safe and carbon-free fusion energy.

Advanced 3D printing offers one potential solution to bridging the science and technology gaps presented by current efforts to make inertial fusion energy (IFE) power plants a reality.

“Now that we have achieved and repeated fusion ignition,” said Tammy Ma, lead for LLNL’s inertial fusion energy institutional initiative, “the Lab is rapidly applying our decades of know-how into solving the core physics and engineering challenges that come with the monumental task of building the fusion ecosystem necessary for a laser fusion power plant. The mass production of ignition-grade targets is one of these, and cutting-edge 3D printing could help get us there.”

A new study suggests there might be a way to prove the notorious Anthropic Principle false.

A new theory related to the second law of thermodynamics describes the motion of active biological systems ranging from migrating cells to traveling birds.

In 1944, Erwin Schrödinger published the book What is life? [1]. Therein, he reasoned about the origin of living systems by using methods of statistical physics. He argued that organisms form ordered states far from thermal equilibrium by minimizing their own disorder. In physical terms, disorder corresponds to positive entropy. Schrödinger thus concluded: “What an organism feeds upon is negative entropy […] freeing itself from all the entropy it cannot help producing while alive.” This statement poses the question of whether the second law of thermodynamics is valid for living systems. Now Benjamin Sorkin at Tel Aviv University, Israel, and colleagues have considered the problem of entropy production in living systems by putting forward a generalization of the second law [2].

Almost 300 binary mergers have been detected so far, indicated by their passing gravitational waves. These measurements from the world’s gravitational wave observatories put constraints on the masses and spins of the merging objects such as black holes and neutron stars, and in turn this information is being used to better understand the evolution of massive stars.

Thus far, these models predict a paucity of black hole binary pairs where each black hole has around 10 to 15 times the mass of the sun. This “dip or mass gap” in the mass range where black holes seldom form depends on assumptions made in the models; in particular, the ratio of the two masses in the binary.

Now a new study of the distribution of the masses of existing black holes in binaries finds no evidence for such a dip as gleaned from the gravitational waves that have been detected to date. The work is published in The Astrophysical Journal.

The search for superconductivity in hydrogen-rich compounds known as hydrides has been an emotional rollercoaster ride for the scientific community. Excitement mounted a few years ago, as hydride experiments had physicists imagining that a Holy Grail, room-temperature superconductivity, might be within reach. But the field was shocked in 2023 by allegations of malpractice and fraud. Now a group of physicists—leading superconductivity experts who aren’t involved in hydride research—has offered an independent assessment of the available body of work on these materials [1]. They conclude that there is overwhelming evidence for superconductivity in hydrides.

“The more I read the foundational literature, and the more I learned about the way that results were being repeated, the more it became clear to me that hydride superconductivity is completely genuine,” says Andrew Mackenzie of the Max Planck Institute for Chemical Physics of Solids in Germany and the University of St Andrews in the UK.

Mackenzie was one of the initiators of the group’s work. “At conferences last spring, guys my age were having lots of young people coming up to ask: What’s going on in hydrides?” he says. After a communal discussion at a superconductivity meeting in Berlin in August, he and other researchers thought that something needed to be done to address young researchers’ concerns. They organized a group that would review available data with the goal of delivering an objective evaluation of hydride superconductivity claims, says Jörg Schmalian of the Karlsruhe Institute of Technology in Germany, who is one of the article’s cosigners.

In 2011 physicists made a surprising observation: A cuprate material exposed to intense pulses of light appeared to superconduct fleetingly at a temperature above its critical temperature. Could this be a clue to finding higher-temperature superconductors? The answer remains unclear. “There are still continuing debates about whether the light-induced state is really superconducting,” says Morihiko Nishida from the University of Tokyo. Now he and his colleagues have provided new hints concerning the nature of the light-induced state and its connection to electronic wave patterns called charge-density waves (CDWs) [1].

The researchers studied two cuprates, called LNSCO and LSCO, that both contain the element lanthanum. These materials superconduct at temperatures below 10 K, but at slightly higher temperatures, they transition to one of several low-conductivity states in which a wave pattern is imprinted onto the electron distribution. Previous work by this group suggested that these CDWs play a role in light-induced superconductivity [2], but it was unclear whether the wavelength—short or long—of the CDWs had any effect.

In their new experiments, Nishida and colleagues fired near-infrared pulses at their cuprate samples and recorded the electron response with a terahertz probe beam. In the CDW region of parameter space, they observed a light-induced conducting state whose frequency matched that of a superconducting resonance effect. The implication that the light-induced state is superconducting needs to be confirmed with other experiments, but the team’s work has revealed that both short-and long-wavelength CDWs play a role. The results have a bearing on models that suggest that the pairing of electrons—a key feature of superconductivity—occurs in CDW states at temperatures above the normal onset of superconductivity (see Synopsis: Picking out Waves in a Material’s Charge Distribution).

Figuring out certain aspects of a material’s electron structure can take a lot out of a computer—up to a million CPU hours, in fact. A team of Yale researchers, though, are using a type of artificial intelligence to make these calculations much faster and more accurately. Among other benefits, this makes it much easier to discover new materials. Their results are published in Nature Communications.

In the field of materials science, exploring the electronic structure of real materials is of particular interest, since it allows for better understanding of the physics of larger and more complex systems, such as moiré systems and defect states. Researchers typically will use a method known as density functional theory (DFT) to explore electronic structure, and for the most part it works fine.

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