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The discover of van der Waals materials that retain magnetic ordering down to monolayers has fostered considerable interest, however, these materials are often hampered by poor environmental stability. Here, Tschudin, Broadway and coauthors study the magnetic properties of CrSBr, using NV-center based magnetometry, detailing magnetization reversal under applied magnetic fields

Electrical control of magnetism in a bilayer of CrI₃ enables the realization of an electrically driven magnetic phase transition and the observation of the magneto-optical Kerr effect in 2D magnets.

The Tomonaga–Luttinger liquid framework can be used to describe 1D quantum systems, spanning fermions, bosons and anyons. In this Review, we discuss the various platforms that can host TLL states, including Josephson junctions, cold atoms and topological materials, and discuss the advances TLL theory can provide in quantum criticality, nonequilibrium dynamics and condensed-matter physics exploration.

Magnetic vortices formed in antiferromagnetic haematite and imprinted on a Co ferromagnetic over-layer have been observed using X-ray magnetic linear and circular dichroism photoemission electron microscopy. These vortex pairs can be manipulated by the application of magnetic fields.

Recently, rich condensed matter physics has emerged from the interplay between band topology and magnetic order. Here, the authors characterize the magnetic Weyl semimetal CeAlGe and find evidence for the role of Weyl fermions in stabilizing the magnetic order above the local transition temperature.

Magnetic adatoms offer an appealing platform for building idealized spin models, but achieving sufficient control to do so is challenging. Now, arrays of Co atoms evaporated on a Cu₂N/Cu(100) surface are shown to behave like a spin-1/2 XXZ Heisenberg chain.

Interacting quantum systems are expected to thermalize, but in some situations in the presence of disorder they can exist in localized states instead. This many-body localization is studied experimentally in a small system with programmable disorder.

In magnetoelectric materials, the magnetization can be controlled by the application of an electric field, making it comparatively easy to switch magnetization, which is attractive for data storage and other proposed devices. Unfortunately, the effect in single-phase materials is typically fairly weak. Here Fogh et al. demonstrate a two orders of magnitude enhancement of the magnetoelectric coupling in LiNi_0.8Fe_0.2PO₄ compared to the parent compounds.

The dynamics of spins in single atomic layers of cuprates and other compounds are important for understanding their properties, such as magnetism and high-temperature superconductivity. Now, spin excitations in isolated single layers of a cuprate have been measured, providing valuable feedback on their magnetic properties.

Honeycomb lattices of divalent, high-spin Co ions are predicted to host dominant Kitaev exchange interactions expanding opportunities to realize the elusive Kitaev Quantum Spin Liquid (KQSL) state. Hydrostatic pressure studies on leading candidate material Na₃Co₂SbO₆ revealed a transition into a low-spin Co state, quenching the orbital degrees of freedom necessary to realize a KQSL state, but leading to possible emergence of quantum paramagnetism in the compressed honeycomb lattice of S=1/2 divalent Co ions.

We demonstrate the magnetic-field induced reversal of antiferromagnetic spins and the electric field modulation of the switching field. The modulation efficiency is significantly high, greater than 4 T nm/V, and this giant modulation efficiency is attributed to the magnetoelectric effect of the antiferromagnetic Cr₂O₃. The magnetoelectric (ME) based mechanism provides a scheme for the energy-efficient, nonvolatile, deterministic 180° switching of the magnetic state in the pure antiferromagnetic (AFM) component. This study represents a great advancement in the AFM-based ME random access memory with ultralow writing power, an inherently fast switching speed and superior robustness to the magnetic state.

The interplay between magnetism and superconductivity in copper oxide superconductors has been a topic of intense research. Now, a systematic resonant inelastic X-ray scattering study of strontium-doped lanthanum cuprate shows that high-energy magnetic excitations persist over a wide doping range.

Electronic nematicity is observed in a heavy-fermion superconductor, CeRhIn₅, suggesting a close link between unconventional superconductivity and the appearance of nematicity.

Controlling magnetic domain wall motion in nanowires requires a thorough knowledge of the depinning mechanisms. Here, the authors show that current-induced intrinsic depinning has a different energy barrier than magnetic field-induced extrinsic depinning, and succeed in quantifying the respective barriers.

More than 40 years ago Berezinskii, Kosterlitz and Thouless (BKT) predicted a state of matter characterized by topological order driven by the binding of vortex-antivortex pairs. Here Tutsch et al.report experimental evidences of BKT physics in a two-dimensional spin-dimer system.

Scale-invariant magnetic anisotropy in RuCl₃ has been revealed through measurements of its magnetotropic coefficient, providing evidence for a high degree of exchange frustration that favours the formation of a spin liquid state.

The origin of high-temperature superconductivity in iron-based materials remains a challenging task to solve, but the concept of orbital differentiation of the charge carriers may be a crucial ingredient to the answer. Here, the authors identify an orbital-selective metal–insulator transition and the opening of a gap in the material Rb_1−xFe_2−ySe₂.

Applications of rare-earth nickelates are hampered by lack of global understanding of the interplay among various degrees of freedom. Here, Mercy et al. propose that the metal-insulator transition of nickelates arises from the softening of an oxygen breathing distortion, providing a united picture of electronic, structural and magnetic properties.

Skyrmion bags—textures comprising multiple skyrmions contained within a larger skyrmion—have been reported in several condensed matter systems. Now an optical analogue of these structures has been observed in plasmonic moiré superlattices.

Ferrimagnets possess multiple spin sub-lattices resulting in a complex magnon band structure and subtle spin transport across interfaces. Here, the authors show how the spin Seebeck effect, the thermal generation of pure spin current, may be an effective tool to study these magnetic excitations.

Applying high pressures to a crystalline material usually dramatically alters its properties. Feng et al.now demonstrate, however, that antiferromagnetism in gadolinium-silicon is robust even under pressures that are large enough to compress the volume of the crystal by one seventh.

Knowledge of the spin structure in parent compounds of unconventional superconductors is crucial for an understanding of the complex physics in these materials. Here, the authors report canted spin structure on the surface as well as on the thin film form of Fe_1+yTe, different from the bulk.

Ferromagnets are an integral part of spintronics because of their spin selectivity, but in combination with superconductors selectivity between different Cooper pairs is required. Here, the authors find evidence for this selectivity in a ferromagnet–superconductor–ferromagnet spin valve.

It is well known that strain can modify the critical temperature below which a material becomes superconducting. Engelmann et al. show that strain does not just modify the critical temperature of iron pnictides but can induce superconductivity in the otherwise non-superconducting undoped phase of BaFe₂As₂.

Millimetre-scale meron lattices that are stable at room temperature and under zero magnetic field can be used as spin injectors in light-emitting diodes, providing 22.5% circularly polarized electroluminescence.

Metals often suffer from reduced strength and ductility after hydrogenation. Here, the authors show hydrogenation can lead to enhancement in strength and ductility accompanied by a large change in magnetic entropy, overcoming the bottlenecks of using amorphous alloys for magnetic refrigerants.

Time-resolved X-ray scattering is utilized to demonstrate an ultrafast 300 ps topological phase transition to a skyrmionic phase. This transition is enabled by the formation of a transient topological fluctuation state.

Magnons (spin-waves) in magnetic materials offer the potential for fast and efficient information processing. To avoid excessive damping due to free electrons, one is typically limited to magnetic insulators as host materials. Here, Poelchen et al demonstrate long lived spin-waves, at terahertz frequencies in the metallic antiferromaget CeCo₂P₂, opening up the possibility of using metallic aniferromagnets for spinwave information processing.

In some iron-based materials, unconventional superconductivity can emerge near a quantum phase transition where long-range magnetic order vanishes. Giovannettiet al.show that the magnetic quantum phase transition in an iron pnictide superconductor is very close to the quantum tricritical point.

Films of the correlated oxide NdNiO₃ form a metallic antiferromagnetic phase that can be identified using electrical currents, raising the prospect of applications in spintronics.

High-temperature superconductors are difficult to model because most conventional theories fail for the strong repulsive interactions between electrons. But what if the correlations are not as strong as believed? Perhaps the magnetic correlations are more essential.

By exploring ultrafast magnetization in several compounds with similar crystal structures but different 4f magnetic elements, the authors show that the Ruderman–Kittel–Kasuya–Yosida interaction controls the spin dynamics.

Femtomagnetism involves the control of magnetism using ultrafast light pulses. Schellekens et al.now show that the spin currents created by femtosecond laser pulses can be used to exert a torque on a magnetic bit, changing its orientation at speeds much faster than possible using electrical means.

Multiple quantum critical behaviors exist in the heavy fermion material CeRhIn5, but their interrelation is less studied. Here, Helm et al. investigate the interrelation of two quantum critical points and other relevant orders, revealing a strongly non-mean-field-like phase diagram.

MnBi2Te4, referred to as MBT, is a van der Waals material combining topological electron bands with magnetic order. Here, Lujan et al study collective spin excitations in MBT, and show that magnetic fluctuations increase as samples reduce in thickness, implying less robust magnetic order.

The temperature-dependent transverse elongation of ferrimagnetic bubbles provides experimental evidence for an evanescent skyrmion Hall effect at zero spin density.

Here, the authors report the experimental realization of a 3D Wannier-type photonic HOTI, which hosts coexisting self-guided topological surface, hinge, and corner states in a single 3D tight binding-like photonic crystal.

Sliding and twisting of van der Waals layers can produce fascinating physical phenomena. Here, authors show that moiré polar domains in bilayer hBN give rise to a topologically non-trivial winding of the polarization field, forming networks of merons and antimerons.