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Altermagnets are arguably the hottest objects in magnetism right now (see Viewpoint: Altermagnetism Then and Now). Over the past year, researchers have delivered experimental evidence for this new type of magnet, but they have yet to harness the behavior for applications. Now three independent groups have proposed methods for electrically tuning the properties of altermagnets [1– 3]. If implemented, the findings could allow the use of altermagnets in next-generation spintronics devices.

Altermagnets can be thought of as a cross between antiferromagnets and ferromagnets. Like antiferromagnets the materials lack net magnetization—the magnetic spins of the atomic lattice are aligned in opposing directions. Like ferromagnets they have magnetically sensitive energy levels and display electronic band structures that are split into spin-up and spin-down bands. This splitting can be used to polarize an electronic current, as one spin state will flow through the material more easily. The combination of these properties could allow researchers to create spintronics devices that operate more rapidly and with greater efficiency than those currently in use, but for that, they first need a way to manipulate the spin properties of an altermagnet.

The proposed methods of the three teams (a group led by Tong Zhou of the Eastern Institute of Technology, Ningbo, China; Libor Šmejkal of the Max Planck Institute for the Physics of Complex Systems, Germany; and a group led by Qihang Liu of the Southern University of Science and Technology, China) all use electric fields for this switching. Controlling magnetism with electricity is particularly attractive because electric fields are much easier to manipulate and integrate into modern electronic devices than magnetic fields. Electrical tuning is potentially also faster (subnanosecond) and could use less energy, two crucial properties for the development of high-speed, low-power spintronic devices.

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Time crystals realized in the so-called quasiperiodic regime hold promise for future applications in quantum computing and sensing.

In ordinary crystals, atoms or molecules form a repeating pattern in space. By extension, in quantum systems known as time crystals, particles form a repeating pattern in both space and time. These exotic systems were predicted in 2012 and first demonstrated in 2016 (see Viewpoint: How to Create a Time Crystal). Now Chong Zu at Washington University in St. Louis and his colleagues have experimentally realized a new form of time crystal called a discrete-time quasicrystal [1]. The team suggests that such states could be useful for high-precision sensing and advanced signal processing.

Conventional time crystals are created by subjecting a collection of particles to an external driving force that is periodic in time. Zu and his colleagues instead selected a quasiperiodic drive in the form of a structured but nonrepeating sequence of microwave pulses. The researchers applied this quasiperiodic drive to an ensemble of strongly interacting spins associated with structural defects, known as nitrogen-vacancy centers, in diamond. They then tracked the resulting dynamics of these spins using a laser microscope.

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BL Lacertae, an enigmatic blazar, has shattered long-held classification norms, leaving astronomers baffled. Originally mistaken for a variable star, this active galaxy emits high-energy jets that have suddenly defied expectations.

Observations from 2020–2023 revealed that BL Lacertae doesn’t neatly fit into any of the three known blazar categories, shifting unpredictably between classifications. This rapid transformation, particularly in X-ray emissions, has sparked intense debate about the underlying physics. Could it be an entirely new type of blazar? Or is an unknown mechanism at play, altering its radiation patterns at unprecedented speeds?

Mysterious Blazar Challenges Astronomers.

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Scientists have unlocked a way to read magnetic orientation at record-breaking speeds using terahertz.

Terahertz radiation refers to the electromagnetic waves that occupy the frequency range between microwaves and infrared light, typically from about 0.1 to 10 terahertz (THz). This region of the electromagnetic spectrum is notable for its potential applications across a wide variety of fields, including imaging, telecommunications, and spectroscopy. Terahertz waves can penetrate non-conducting materials such as clothing, paper, and wood, making them particularly useful for security screening and non-destructive testing. In spectroscopy, they can be used to study the molecular composition of substances, as many molecules exhibit unique absorption signatures in the terahertz range.

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A new optical amplifier is changing the game. Unlike conventional amplifiers, this chip-based breakthrough leverages optical nonlinearity rather than rare-earth elements, allowing signals to strengthen themselves. The result? A compact, high-performance device with a bandwidth three times wider than traditional solutions.

Expanding the Limits of Optical Amplification

Modern communication networks rely on optical signals to transmit massive amounts of data. However, like weak radio signals, these optical signals need amplification to travel long distances without degrading. For decades, erbium-doped fiber amplifiers (EDFAs) have been the standard solution, extending transmission range without requiring frequent signal regeneration. Despite their effectiveness, EDFAs operate within a limited spectral range, restricting the growth of optical networks.

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Instead of searching for familiar biosignatures like oxygen, they’re investigating methyl halides – gases produced by microbes on Earth that could be more easily detected in the thick hydrogen atmospheres of Hycean planets. The James Webb Space Telescope.

The James Webb Space Telescope (JWST or Webb) is an orbiting infrared observatory that will complement and extend the discoveries of the Hubble Space Telescope. It covers longer wavelengths of light, with greatly improved sensitivity, allowing it to see inside dust clouds where stars and planetary systems are forming today as well as looking further back in time to observe the first galaxies that formed in the early universe.

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With rapid technological advances, social media has become an everyday form of human social interactions. For the first time in evolutionary history, people can now interact in virtual spaces where temporal, spatial, and embodied cues are decoupled from one another. What implications do these recent changes have for socio-cognitive phenotypes and mental disorders? We have conducted a systematic review on the relationships between social media use and mental disorders involving the social brain. The main findings indicate evidence of increased social media usage in individuals with psychotic spectrum phenotypes and especially among individuals with disorders characterized by alterations in the basic self, most notably narcissism, body dysmorphism, and eating disorders.

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Supersolids are a strange quantum state of matter that combines properties of solids and liquids.

Now they’ve gotten even more mind-bending, as scientists have transformed light itself into a supersolid. It’s a breakthrough that could lead to new quantum and photonic technologies.

Beyond the everyday solids, liquids, gases, and plasmas, an entire zoo of exotic states of matter exists. Long theorized but only recently created, a supersolid has a crystalline structure like a regular solid, but it can also, counterintuitively, flow freely like a fluid.

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As for these new JWST findings. Poplawski told Space.com: “It would be fascinating if our universe had a preferred axis. Such an axis could be naturally explained by the theory that our universe was born on the other side of the event horizon of a black hole existing in some parent universe.”

He added that black holes form from stars or at the centers of galaxies, and most likely globular clusters, which all rotate. That means black holes also rotate, and the axis of rotation of a black hole would influence a universe created by the black hole, manifesting itself as a preferred axis.

“I think that the simplest explanation of the rotating universe is the universe was born in a rotating black hole. Spacetime torsion provides the most natural mechanism that avoids a singularity in a black hole and instead creates a new, closed universe,” Poplawski continued. “A preferred axis in our universe, inherited by the axis of rotation of its parent black hole, might have influenced the rotation dynamics of galaxies, creating the observed clockwise-counterclockwise asymmetry.

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