Altermagnetism: The Third Form of Magnetism Unveiled

Introduction: A New Magnetism Emerges

For over a century, physicists recognized two fundamental kinds of magnetic order: ferromagnetism and antiferromagnetism. Late in 2024, scientists confirmed evidence of a third kind of magnetism called altermagnetism. This new class of magnetism combines some characteristics of the other two and could greatly impact technology – potentially boosting computer memory storage, saving energy and rare-earth materials, and even aiding the quest for better superconductors . The discovery was significant enough that the journal Science named altermagnetism one of the top physics breakthroughs of 2024.

The Three Forms of Magnetism in a Nutshell

• Ferromagnetism: All microscopic magnetic moments (spins of electrons or atoms) align in the same direction. This uniform alignment produces a net magnetic field – it’s why materials like iron or cobalt stick to a fridge. Ferromagnets have been used for data storage (e.g. in hard drives or MRAM), because the aligned spins can represent binary data. However, their strong external fields can make them unstable for dense storage: a stray field can erase or flip bits nearby (a strong magnet could wipe a hard drive). Ferromagnetic memory devices also face speed limits, as flipping the magnetization is a relatively slow, GHz-frequency process governed by the material’s magnetic inertia.

• Antiferromagnetism: As the name suggests, this is the opposite alignment. Adjacent spins point in opposite (antiparallel) directions, often in a checkerboard-like pattern. This cancels out any macroscopic magnetization – antiferromagnetic materials have no external magnetic field. Because of this, an antiferromagnet won’t stick to your refrigerator; its internal magnetic order is invisible externally (imagine little north-south magnets alternating so perfectly their fields mute each other). Antiferromagnets are extremely stable and resistant to external magnetic interference. This makes them attractive for ultra-dense memory (no crosstalk between bits), but there’s a catch: with no overall magnetic field or easy way to read their state, they’ve been harder to utilize for storage – they appear “magnetically silent” without specialized methods to sense their internal state.

• Altermagnetism: This newly identified form is a hybrid of the two above – a collinear magnetic order that sits between ferromagnetism and antiferromagnetism. Like an antiferromagnet, an altermagnet has neighboring spins that are antiparallel, yielding zero net magnetization (no external field). However, there is a twist in how those opposite spins are arranged in the crystal. The crystal’s symmetry is such that each little magnetic moment is rotated relative to its neighbors, rather than just linearly opposite. All the electrons’ spins point uniformly along a certain twisted direction in each sub-lattice. In effect, an altermagnet has the “hidden” alternating spin order of an antiferromagnet but still produces a spin-polarized current like a ferromagnet. From afar it looks inactive (no north/south poles), yet on the nanoscale it exhibits a strong internal magnetic polarization.

Figure – Comparing Spin Orders: In ferromagnets (left), all spins align in the same direction, giving a nonzero macroscopic magnetization. In antiferromagnets (center), spins alternate up/down in a pattern related by an inversion or translation symmetry, yielding no net magnetization. In altermagnets (right), spins also alternate antiparallel (no net magnetization), but the two sub-lattices are related by a rotation symmetry (curved arrow) rather than a simple inversion. This symmetry “twist” means the electronic bands in an altermagnet are spin-split (like a ferromagnet’s bands) even though the overall magnetization cancels .

Visualizing spin densities in an altermagnetic material. Different colors/arrows indicate opposite spin orientations on different sublattices (Credit: Libor Šmejkal & Anna Birk-Hellenes).

Origins and Theoretical Development

The concept of altermagnetism is very new. It was first theorized in 2019 when researchers at Johannes Gutenberg University Mainz (JGU) in Germany and collaborators noticed a result in a material that couldn’t be explained by the two “legacy” types of magnetism . In fact, between 2019 and 2021, several theoretical groups identified the possibility of a new fundamentally distinct magnetic order. Initially, different names were used for this predicted phase, but in 2022 the term “altermagnetism” (proposed by physicist Libor Šmejkal and colleagues) gained traction. The name reflects the idea of alternating magnetism – a magnetic order that alternates like an antiferromagnet but in an alternative symmetry mode.

Once theorists had a clear definition, they combed through databases of materials. By 2022, over 200 candidate materials were predicted to exhibit altermagnetic order . These candidates spanned all kinds of crystals – insulators, semiconductors, metals, even some superconductors – including many well-known compounds that had been studied for years without realizing their true magnetic nature . This was exciting because it suggested altermagnetism wasn’t a rare quirk of an exotic material; it could be a widespread phenomenon “hiding in plain sight” in common crystals.

One early clue came from a classic material: manganese telluride (MnTe). MnTe was long classified as a typical antiferromagnet (neighboring Mn spins antiparallel). But theorists noticed that MnTe’s crystal symmetry is not the same as textbook antiferromagnets – it hinted at the altermagnetic pattern. Similarly, ruthenium dioxide (RuO₂) and other compounds were flagged as likely altermagnets. These theoretical predictions set the stage for experimentalists to verify this third form of magnetism.

Experimental Proof and How Altermagnetism Works

Demonstrating altermagnetism experimentally was challenging – since an altermagnet has no net magnetic field, you can’t just use a compass or magnetometer to detect it. Instead, scientists looked for more subtle signatures in the electronic structure of candidate materials.

First evidence (2024): In early 2024, a team led by Prof. Hans-Joachim Elmers at Mainz provided the first conclusive evidence of altermagnetism. They used momentum-resolved electron microscopy techniques at DESY (Deutsches Elektronen-Synchrotron) to visualize how electrons in RuO₂ behave. By firing X-rays at a thin film of RuO₂ and measuring emitted electrons, they could map the electrons’ velocities and spins (in what physicists call momentum space). The result showed the hallmark of altermagnetism: for electrons moving in a given direction through the crystal, the spins were uniformly aligned (all those electrons had the same spin). Yet, if you consider the crystal as a whole, there were equal numbers of opposite spins moving in various directions, canceling out any overall magnetization. This experiment, published in Science Advances in January 2024, demonstrated the predicted “hidden” spin polarization of an altermagnet’s electronic bands in RuO₂.

Shortly after, an international collaboration (Czech Academy of Sciences, EPFL, PSI, University of Nottingham, and others) focused on manganese telluride (MnTe). They used advanced spin-resolved photoemission spectroscopy at synchrotron X-ray facilities (the Swiss Light Source and Sweden’s MAX IV) to probe MnTe. In late 2024, they reported in Nature that MnTe’s electronic bands are indeed “spin-split” – meaning the energy levels for spin-up electrons diverge from those for spin-down electrons. Importantly, MnTe still had no net magnetization (the spins on neighboring Mn atoms cancel out). This combination of vanishing net magnetization and broken spin degeneracy is exactly what theory predicts for altermagnets, and it’s something a conventional antiferromagnet cannot do. In a normal antiferromagnet, the magnetic order alone should not lift the Kramers spin degeneracy of electronic states – if you flip all spins and shift the position, the system looks the same, keeping each energy level doubly (spin) degenerate. But in MnTe they observed that this degeneracy is lifted by the magnetic order, confirming MnTe is neither a standard ferromagnet nor a standard antiferromagnet, but an altermagnet. One scientist noted that seeing MnTe behave this way was a smoking gun: “when the scientists saw the lifting of Kramers spin degeneracy, accompanied by the vanishing net magnetisation, they knew they were looking at an altermagnet”.

How it works (symmetry twist): The physical mechanism of altermagnetism boils down to symmetry. In an antiferromagnet, if you flip all spins and then shift the lattice (or invert it through a point), each atom’s environment looks the same as before; this symmetry operation relates the two opposite sublattices. In an altermagnet, if you flip all spins, you’d have to rotate the lattice to map each atom onto an equivalent one . For example, think of a square lattice where spins alternate up/down in a checkerboard. If the checkerboard is oriented normally, an inversion through the center of a square might map an up-spin to a down-spin – that’s antiferromagnetism. But if the checkerboard is rotated 45°, the mapping might require a 90° rotation of the whole lattice. That rotation symmetry (as opposed to a simple inversion or translation) is what defines many altermagnets . Crucially, rotational symmetry doesn’t preserve the momentum (k-space) orientation of electrons in the way a translation or inversion does, so the up-spin and down-spin electrons are no longer bound to have the same energy. In other words, the symmetry “twist” in altermagnets breaks the usual pairing of spins in energy levels.

Another way to picture it: in an altermagnet, electrons moving east might all be spin-up, while those moving west are spin-down (just as a conceptual example). If you look at the whole crystal, there are as many electrons moving east (spin-up) as west (spin-down), so any magnetic effect cancels out globally. But if you isolate one direction of current, it’s fully spin-polarized! This is why researchers say “it’s not about where the electrons are located, but only about the direction they’re moving” that matters. The alignment of spin with momentum is sometimes called spin-momentum locking in momentum-space, a hallmark of altermagnetic order predicted by Jairo Sinova, Libor Šmejkal, and colleagues years earlier.

In summary, altermagnets break time-reversal symmetry (like ferromagnets do) – you can tell an altermagnet from its mirror-image spin flipped self, because the energy band structure changes. This means altermagnets can exhibit phenomena usually unique to ferromagnets (more on those soon). Yet, altermagnets also have a symmetry that flips all spins and moves atoms (via rotation), leading to perfect cancellation of magnetization (like an antiferromagnet). It’s a new kind of collinear magnetic order that had been overlooked in materials we thought we understood.

Distinguishing Characteristics of Altermagnets

To clarify what sets altermagnets apart, here are their key features contrasted with ferromagnets and antiferromagnets:

• No External Magnetic Field: Altermagnets have zero net magnetization, just like antiferromagnets. If you measure the bulk magnetization, you get nothing – two sublattices of opposite spins cancel out. This is in contrast to ferromagnets, which have a strong net magnetization. As a result, an altermagnetic crystal by itself won’t produce a magnetic field in space (no fridge-sticking, no interference with nearby electronics). This property is crucial for stability and for avoiding magnetic crosstalk in devices.

• Spin-Polarized Electron Bands: Despite no net moment, an altermagnet’s electronic structure behaves more like a ferromagnet’s. Ferromagnets split the energy levels of electrons depending on spin (one spin orientation is energetically favored), which leads to phenomena like spin-polarized currents and the anomalous Hall effect. Antiferromagnets, by symmetry, keep spin-up and spin-down bands paired (degenerate) so they don’t show a net spin polarization in transport. Altermagnets do have spin-split bands and Fermi surfaces – meaning an electron’s energy does depend on whether it’s spin-up or spin-down. We can say an altermagnet is magnetically “invisible” externally but internally polarized. Experiments confirmed this by seeing band splitting in MnTe without net magnetization. Thus, if you send a current through an altermagnet in a particular direction, it can be strongly spin-polarized (all one spin), similar to a ferromagnet’s current.

• Symmetry and “Alternation”: The term altermagnetism highlights that spins alternate (like in an antiferromagnet) but via a different symmetry operation (rotation) . In standard antiferromagnets, the two sublattices are usually related by a simple spatial inversion or translation, which enforces opposite spins to have identical electronic environments. In altermagnets, the relation is a rotation or other symmetry that does not preserve the orientation of momentum space. This symmetry difference is what allows altermagnets to break Kramers degeneracy (spin degeneracy) without a net magnetization. It’s a bit abstract, but fundamentally this is why altermagnetism is considered a distinct third category – it’s defined by a different symmetry principle than the other two categories of ordered magnetism.

• Collinear but Compensated: Altermagnetic order is collinear – all spins are either “up” or “down” along one axis (no canted or spiral arrangements). This is the same as ferromagnets and (simple) antiferromagnets, where you can point to a single axis and say all moments are parallel or antiparallel to it. However, unlike a ferromagnet (all parallel) or a ferrimagnet (unequal opposing sublattices), an altermagnet’s two opposite-spin sublattices exactly compensate each other by symmetry. In effect, an altermagnet can be thought of as a fully compensated magnet that still exhibits ferromagnet-like behavior in each sublattice. This concept is somewhat related to earlier ideas like “compensated ferrimagnets” or “half-metals” where net moment can cancel out, but altermagnets achieve it in a symmetry-protected way that ensures exact cancellation along with spin splitting.

• Stability and Domains: With no macroscopic magnetic field pushing on them, altermagnets should be as magnetically stable as antiferromagnets. They won’t spontaneously demagnetize due to stray-field energy the way large ferromagnets do (ferromagnets tend to form domains to minimize self-field energy, but an altermagnet has no self-field). One practical challenge is that if an altermagnet sample does break into multiple magnetic domains, many of its novel effects (like a net spin current or Hall effect) could cancel out, since different domains might carry opposite polarizations. Ensuring a single-domain state (all spins oriented in one global pattern) is something researchers are working on for real applications. The good news is that a single-domain altermagnet is actually the lowest-energy state (no field means no energetic penalty for being single-domain), so it might be easier to maintain than in ferromagnets.

In short, altermagnets behave like “hidden ferromagnets.” They have all the microscopic breakings of symmetry that a ferromagnet has (hence affecting electron motion and spin), but none of the visible magnetic dipole effect outside the material. This unique combination is what makes them exciting for technology.

Potential Technological Applications and Impact

Altermagnetism isn’t just a laboratory curiosity – it could be transformative for several technologies, especially in the realm of computing and data storage. Here are some key applications and why altermagnets are promising:

• Ultrafast Memory and Logic Devices: Perhaps the most buzzworthy advantage of altermagnets is speed. Traditional ferromagnetic devices (like those in MRAM – Magnetoresistive Random Access Memory) operate at gigahertz frequencies, because flipping a ferromagnet’s orientation is limited by its precession (ferromagnetic resonance) in the GHz range. Altermagnets, on the other hand, are predicted to have resonant frequencies on the order of terahertz – about 1000 times higher. In practical terms, this means altermagnetic memory bits could potentially switch states up to a thousand times faster than ferromagnetic bits. Researchers in one study demonstrated that by using an altermagnetic material in a micro-device, they could potentially reach THz operation speeds, vastly outpacing today’s tech. Faster switching translates to faster processors and memory – imagine cache or RAM that operates in the terahertz regime, drastically reducing computing bottlenecks. This could enable high-speed, real-time processing for advanced computing tasks.

• Spintronics with No Crosstalk: Spintronics refers to technologies that use the electron’s spin state (up or down) to carry information, as opposed to (or in addition to) its charge. Ferromagnets have been the go-to materials for spintronics because they create spin-polarized currents and large magnetoresistance effects (needed for reading and writing spin information). However, ferromagnets come with a glaring issue in chip architectures: their stray magnetic fields cause crosstalk between adjacent devices. If you pack ferromagnetic bits too closely, they can influence each other (like little bar magnets jostling) – this limits how small and dense memory cells can be without shielding. Antiferromagnets solve the crosstalk issue (no stray field), but provide negligible spin-dependent signals to actually use. Altermagnets combine the best of both: no large-scale field to cause interference, yet strong spin-dependent effects for read/write . This means we could build ultra-dense memory chips or spin-based logic where bits sit next to each other without interference, and we can still easily read their state via spin-polarized currents or tunneling magnetoresistance. As one report put it, altermagnets bring “merits that were regarded as incompatible” into a single material . This paves the way for scalable spintronic devices – e.g., an altermagnetic MRAM array with terabit-per-inch densities, or logic circuits where data is encoded in spin without worrying about neighboring bits flipping each other.

• Higher Capacity and Energy-Efficient Data Storage: Because altermagnetic bits don’t produce external fields, they could be made much smaller and closer together than ferromagnetic bits, boosting data storage capacity. Additionally, writing data could be more energy-efficient. In many magnetic memories, you have to use current to flip a magnet, and if bits interfere, you need extra energy margins. Altermagnets would require less energy to reliably switch since you don’t fight stray fields or risk unintended flips. Also, some altermagnets might allow novel writing schemes (like using polarized light or electric fields exploiting magneto-optical or piezoelectric coupling, since their symmetry is unusual – though research is ongoing). Industry experts note that replacing conventional magnetic materials with altermagnets in memory devices could cut energy consumption and even reduce reliance on scarce materials . One reason is that many ferromagnets used in high-performance contexts contain rare earth elements (for example, neodymium in powerful magnets), whereas many altermagnet candidates (like Mn, Ru, O-based compounds) do not. This could make technology not only greener (lower energy, no rare-earth mining) but also cheaper long-term.

• Tunneling Magnetoresistance (TMR) Devices: TMR is the basis of reading data in MRAM and hard disk read heads – it’s a quantum effect where electrical resistance through an insulating barrier depends on the relative alignment of magnetizations. Ferromagnets give a high TMR (big difference between parallel vs antiparallel alignment), whereas antiferromagnets can’t be directly used in a standard TMR junction (no net magnetization to align). Altermagnets, with their spin-polarized bands, could act as one or both electrodes in a TMR device, potentially yielding large signals without stray field issues. Moreover, because their intrinsic switching is so fast, we could see terahertz-frequency spin-torque oscillators or ultrafast magnetic tunnel junctions. In fact, researchers have proposed altermagnetic tunnel junctions as a new type of memory element with enormous speed and minimal cross-talk.

• Neuromorphic Computing and Spin Logic: Beyond binary data storage, the rich spin dynamics of altermagnets might be useful in neuromorphic devices – hardware designed to mimic brain-like networks. Some proposals suggest using spin waves or spin currents to simulate neurons and synapses. Altermagnets, supporting high-frequency spin waves (THz) and giant spin current ratios, could allow for very fast, analog-like computing elements that process information via spin interactions. Their lack of net magnetization also means many such “neurons” could be packed densely in 3D without mutual disturbance, which is attractive for neuromorphic architectures.

• Superconductivity and Quantum Technology: Interestingly, altermagnets might help advance superconductors and quantum devices. Normally, magnetism and superconductivity don’t mix well – ferromagnets tend to destroy conventional superconductivity because a magnetic field breaks the Cooper pairs in a superconductor. But an altermagnet provides an environment of broken time-reversal symmetry without a disruptive external field. This opens up possibilities to explore unconventional superconducting states that coexist with this hidden magnetism. For example, some theorists speculate that coupling an altermagnet with a superconductor could stabilize exotic pairing mechanisms (like spin-triplet pairing, which is compatible with internal spin polarization). It’s also a new platform for studying quantum phenomena: the combination of spin splitting and no net field might give rise to unique topological states or excitations in crystals. While these ideas are nascent, the discovery of altermagnetism provides a playground for quantum materials research – possibly aiding in the design of faster quantum memory elements or resilient qubits that exploit spin states immune to external magnetic noise.

• Integration into Current Tech: A practical advantage is that many altermagnets are compatible with existing semiconductor processes. They can often be grown as thin films and integrated with other materials. For instance, thin films of RuO₂ or MnTe can be deposited on substrates, and they don’t require special handling like some fragile quantum materials. Engineers note that altermagnets could be dropped into current device architectures relatively easily, without needing magnetic shielding between components. The lack of net field also means less electromagnetic interference (EMI), which is beneficial as devices shrink. Early-stage experiments have already created microscopic altermagnetic devices, indicating that scaling down to chip-level is feasible.

In summary, altermagnetic materials promise faster, smaller, and more energy-efficient memory and logic. They represent a way to push spintronic technology to its full potential by removing the trade-off between magnetic readability and scalability. Replacing or augmenting ferromagnets with altermagnets in data storage could drastically improve performance – one study suggests operation speeds “up to a thousand times faster” than some existing microelectronic components, and with far less energy loss as heat. They also alleviate the need for certain expensive materials and could reduce the environmental footprint of high-tech manufacturing. While it may take some years for these materials to mature into commercial products (as is always the case in materials science), the path forward is lit: researchers are now intensely exploring how to control and harness altermagnetism under different conditions and in device configurations .

Verifying the Hype: Cross-Checking Key Claims

Whenever a new discovery makes headlines, it’s wise to check what peer-reviewed science says. Many claims about altermagnetism in popular articles (like Discover Magazine) are strongly supported by scholarly research:

• “Combines advantages of ferromagnets and antiferromagnets”: This is essentially how physicists define altermagnets. As Prof. Elmers (one of the discoverers) explained, “Their neighboring magnetic moments are always antiparallel… so there is no macroscopic magnetic effect, but, at the same time, they exhibit a spin-polarized current – just like ferromagnets.”. Multiple sources echo that altermagnets bridge the gap between the two traditional classes . So this claim is not hype – it’s the fundamental feature of the new phase.

• Memory devices a thousand times faster: The notion of vastly faster operation comes from the physics of spin dynamics. Ferromagnetic bits are limited by gigahertz switching (their spins precess at a few nanoseconds period). Altermagnets can in principle switch in picoseconds (terahertz) because their spin orientation can oscillate at much higher frequencies. A perspective in Physical Review X pointed out that the characteristic resonance frequency of altermagnets could be three orders of magnitude higher than that of ferromagnets. Experimental groups (like those at Nottingham and MAX IV) have explicitly stated potential “speeds up to a thousand times faster” for memory and switching devices based on their altermagnetic prototypes. Thus, the dramatic speed claim is grounded in real physical differences and early experimental validation, not just speculation.

• Increased storage density & energy savings: These advantages come from the lack of stray fields and the ability to carry spin info at smaller scales. The EPFL/Czech team writes that ferromagnetic memory faces “practical limitations on scalability as it causes crosstalk between bits,” whereas antiferromagnets solve that but lose the useful spin effects – “here enter altermagnets with the best of both: zero net magnetisation together with strong spin-dependent phenomena” . With no magnetic crosstalk, bits can be smaller and closer, boosting density. And if bits switch faster, you can get the same work done with shorter pulses of current, potentially reducing energy per operation (plus no need for power-hungry error-correction for stray flips). One press release explicitly suggests altermagnets could significantly increase memory capacity and be “the solution to a major challenge in spintronics,” making it easier to read information via spin polarization. Another report notes using altermagnets could cut reliance on heavy rare-earth elements and lower device power usage, contributing to lower carbon emissions . These claims are in line with expert opinions, not just journalistic optimism.

• Impact on superconductivity: The Discover article mentioned altermagnets could “boost the quest for superconductivity.” While that might sound grandiose, there is a scientific rationale behind it. Researchers have indeed pointed out that altermagnets provide a new playground for exploring how magnetism interacts with superconducting states. Since altermagnets break time-reversal symmetry without a net field, they could help stabilize or reveal unconventional superconductors (like those that require broken symmetry). This area is speculative but serious enough that it’s discussed in research contexts as a promising direction. In fact, the discovery of altermagnetism is seen as enriching our overall understanding of condensed matter physics and possibly impacting diverse fields from topology to superconductivity. So this claim, while forward-looking, is rooted in expert commentary.

In short, the excitement about altermagnetism is strongly supported by experimental evidence and theoretical understanding. It’s not a case of media hype outpacing the science – if anything, the scientific community itself is heralding altermagnetism as a genuine breakthrough. As noted, Science magazine included it in 2024’s major breakthroughs, indicating broad peer appreciation.

Conclusion and Outlook

Altermagnetism’s discovery adds a new branch to the magnetic family tree, fundamentally expanding how we classify magnetic materials. It’s rare in physics to identify a new foundational phase of matter, especially in a field as established as magnetism. This “third type” of magnetism is not just theoretically fascinating – it’s a happy hybrid that may solve practical issues in modern technology. By offering ferromagnet-like functionality without ferromagnet-like drawbacks, altermagnets could become key ingredients in next-generation memory chips, spintronic sensors, and high-speed processors.

The research momentum is strong. Now that scientists know what to look for, they have realized that many materials sitting in labs or even in old mineral collections were altermagnets all along. This means there’s a trove of known compounds (and likely many yet-to-be-synthesized ones) that can be explored for altermagnetic behavior. Efforts are underway to characterize these materials’ properties, optimize them (e.g. achieving single magnetic domains, tuning their ordering temperatures), and integrate them into device prototypes. As one scientist put it, “Altermagnetism is actually not something hugely complicated. It is something entirely fundamental that was in front of our eyes for decades without noticing it… It exists in many crystals that people simply had in their drawers.” Now that it’s “brought to light,” researchers worldwide can dive in, accelerating progress.

In the coming years, we may witness altermagnetic memory elements being demonstrated, perhaps a new type of MRAM that operates at THz frequencies or spin-logic circuits that pack millions of non-interfering nano-magnets on a chip. There is also interest in topological altermagnets (where the band structure has protected states) and exploring if altermagnets can be switched by ultrafast laser pulses (taking advantage of their high-frequency dynamics). The implications span from improving classical computing hardware to informing quantum materials research.

In conclusion, altermagnetism enriches both our understanding of magnetic order and our toolkit for technology. It reminds us that even in well-trodden fields, nature can still surprise us with new layers of complexity. As research continues, altermagnets might move from the pages of Nature into the chips of our future devices, embodying the synergy of stability and functionality that engineers have long sought in magnetic materials. The discovery of this third form of magnetism isn’t just an academic milestone – it could herald a new era of faster, greener, and more robust electronics, all thanks to a clever twist in how spins can align.

Sources:

• Smaglik, P. (2025). Discover Magazine – There Is a New, Third Category of Magnet and it Could Boost Computer Memory.

• Fedchenko, O. et al. (2024). Science Advances, 10(5) – Experimental evidence of altermagnetism in RuO₂.

• EPFL News & PSI (2024). Nature – Confirmation of altermagnetism in MnTe; EPFL press release .

• Šmejkal, L., Sinova, J., Jungwirth, T. (2022). Phys. Rev. X, 12, 040501 – “Emerging Research Landscape of Altermagnetism” (theoretical overview).

• Physics APS Commentary (2023). Altermagnetism Then and Now – background and implications.

• Earth.com News (Feb 2025). Third form of magnetism… could transform electronics .

• Press releases: JGU Mainz (Feb 2024) – Altermagnetism experimentally demonstrated; JGU/EurekAlert (Jan 2025) – Science lists the discovery of altermagnetism as a breakthrough.