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The Mermin-Wagner theorem states that for short-range isotropic interactions, magnetic order in two dimensions is destroyed by magnetic fluctuations at finite temperatures. Observing this situation is challenging due to the finite size of typical laboratory samples. Here, Kiaba et al observe the suppression of magnetic order in oxide superlattices, at the thickness of the superlattice layers are reduced to one monolayer.

The identification of the magnetic-fluctuation mode at a quantum phase transition of the archetypical heavy-fermion compound Ce_1−xLa_xRu₂Si₂ indicates that quantum criticality in this system is governed by collective antiferromagnetic behaviour, rather than by local magnetic moments as has been suggested.

Programmable topological dipoles could be used in stimuli-responsive materials. Now it is shown that confinement of an apolar liquid crystal results in controllable polar arrangements of elastic dipoles.

Antiferromagnets are promising candidates to build terahertz spintronic devices. However, manipulating and detecting their terahertz spin dynamics remains key challenges. Here, Rongione et al. demonstrate both broadband and narrowband terahertz emission from an antiferromagnet/heavy metal heterostructure using spin-phonon interactions.

Domain walls forming within magnetic nanowires offer a valuable degree of freedom with which to explore possible future information storage and processing architectures. By taking advantage of the piezoelectric characteristics of perpendicularly magnetized GaMnAsP/GaAs nanowires, large variations in the current-induced domain wall mobilities are obtained.

As ferroelectric and magnetic ordering coexist in multiferroic materials, they might be used for memory applications, but only if the multiferroic phase is stable at room temperature. Here, the authors find such a phase in cupric oxide, whose spin-spiral multiferroicity is stabilized by pressure.

We establish a spin nematic phase in the square-lattice iridate Sr₂IrO₄ and find a complete breakdown of coherent magnon excitations at short-wavelength scales, suggesting a many-body quantum entanglement in the antiferromagnetic state.

The study of frustrated magnet systems has unveiled a range of novel physical phenomena and continues to attract interest for in fields such as quantum spin liquid theory and high-temperature superconductors. Here, the authors use ab-initio calculations and a spin-wave analysis to demonstrate that an order-from-disorder phenomenon contributes to the columnar antiferromagnet ordering of BaCoS2.

Dzyaloshinskii–Moriya interaction (DMI) is one of the key factors to control the chiral spin textures in spintronic applications. Here the authors demonstrate the correlation of the DMI with the anisotropy of the orbital magnetic moment and magnetic dipole moment in Pt/Co/MgO ultrathin trilayers.

Kosterlitz–Thouless–Halperin–Nelson–Young (KTHNY) theory describes the melting of an ordered two-dimensional phase to a disordered phase, via a quasi-ordered ‘hexatic’ phase. Magnetic skyrmions, as a phase of two-dimensional quasi-particles may be expected to exhibit a KTHNY melting process, however, observing such a phase transition is difficult. Herein, Meisenheimer et al study the formation of magnetic skyrmions in (Fe_0.5Co_0.5)₅GeTe₂, and, via physical confinement at device scale, succeed in obtaining an ordered skrymion phase.

There has been substantial progress in observing and understanding nonlinear transport properties of non-centrosymmetric materials in recent years. This Review surveys the interplay between symmetry and nonlinear phenomena, and how nonlinear transport probes quantum properties of solids. The authors also highlight the potential applications of these nonlinear transport effects in fields such as spintronics, orbitronics and energy harvesting.

Skyrmions are topological spin textures, which have been proposed as useful for a diverse array of applications. One such proposal is to make use of a skyrmion’s thermally activated Brownian-like diffusive motion for unconventional computing and true random number generation. Here, Dohi et al show how, in a synthetic antiferromagnet, this diffusive motion can be significantly enhanced.

An intrinsic antiferromagnetic topological insulator, MnBi₂Te₄, is theoretically predicted and then realized experimentally, with implications for the study of exotic quantum phenomena.

Spinons, or fractionalized collective excitations, have been reported in 1D systems but are debated in higher dimensions. Here the authors show that a heterostructure-based approach induces liquid-like spin dynamics in a 2D Heisenberg antiferromagnet, with isotropic continuum excitations extending to low energies.

Honeycomb lattices with interacting spins can host rich magnetic behaviour; however, typically features are complicated by additional interactions. Here, the authors perform neutron scattering on YbCl₃, which exhibits near perfect two-dimensional magnetism, providing a benchmark for other materials.

In the typical spin-hall effect, spin-current, charge current, and spin polarisation are all mutually perpendicular, a feature enforced by symmetry. Here, using an anti-ferromagnet with a triangular spin structure, the authors demonstrate a spin-hall effect without a perpendicular spin alignment.

In the layered magnetic semiconductor CrSBr, emergent light–matter hybrids (polaritons) increase the spectral bandwidth of correlations between the magnetic, electronic and optical properties, enabling largely tunable optical responses to applied magnetic fields and magnons.

The control and manipulation of domain walls in perpendicularly magnetized nanowires by means of an electric current has gained attention for possible device applications. Now, the depinning of domain walls in Pt/Co/Pt nanowires is shown to be driven by the spin Hall effect.

Magnetic fields are thought to have been influential in the formation of our solar system. Here, the authors observe thermomagnetically stable, non-uniformly magnetized kamacite grains within chondritic meteorites, and calculate the grains to retain recordings of these magnetic fields.

Antiferromagnets have a variety of attractive features for spintronic devices; they are inherently robust against external magnetic fields, and have fast, terahertz, dynamics. However, terahertz magnons are usually strongly damped. Here, Choe, Lujan and coauthors find that the zone boundary magnons in the AFM insulator CoTiO3 exhibit long lifetimes.

Mn3Sn is an anti-ferromagnetic material which displays a large magneto-optical Kerr effect, despite lacking a ferromagnetic moment. Here, the authors show that likewise, Mn3Sn, also presents a particularly large magneto-optical Voigt signal, with a negligible change in the quench time over a wide temperature range.

Van der Waals magnetic materials are characterized by strong magnetic interactions within each van der Waals layer, while the interaction between the layers is typically weaker. Here, Liu, Su, Gu and coauthors find a magnetic phase transition in the van der Waals magnet, NiI₂, under hydrostatic pressure, which they associate with the interlayer magnetic interaction.

Pyrochlore iridates have been studied for their potential to explore novel phases due to the interplay of correlations, spin-orbit interaction, and more recently dimensionality. Here the authors report a chiral spin-liquid-like state in (111)-oriented Y₂Ir₂O₇ thin films which emerges at a reduced thickness.

Magnetically intercalated transition metal dichalcogenides provide a platform to study the interplay of magnetism, electronic band structures, and correlations. Here the authors demonstrate a nearly magnetization-free anomalous Hall effect, collinear antiferromagnetism and non-Fermi liquid behavior in V_1/3NbS₂.

Resonant inelastic X-ray scattering at the 4d-edge reveals dispersive magnetic excitations in SrRu₂O₆, providing insight into the origin of its high Néel temperature.

Antiskyrmions are topological spin textures with negative vorticity. Like skyrmions, they have considerable technological promise, but have only been stabilised in Heusler compounds. Here, Heigl et al. succeed in stabilising first and second order antiskyrmions in a new class of materials.

Quantum-metric-induced nonlinear transport, including the nonlinear anomalous Hall effect and a diode-like response, is observed in thin films of a topological antiferromagnet, providing a means to design magnetic nonlinear devices.

A new approach to magnetic switching by spin–orbit torque uses interlayer exchange coupling to overcome the need for an external magnetic field.

The use of antiferromagnetic materials in spintronic devices has been proposed as an attractive alternative to ferromagnets, but only a few suitable materials are known. Here, the authors synthesize a new antiferromagnet (AFM)—tetragonal epitaxial CuMnAs—and show that it is ideal for spintronic applications.

The dynamics of the magnetic correlations after photo-doping Sr₂IrO₄ are studied through ultrafast time-resolved resonant inelastic X-ray spectroscopy. The timescales are found to depend on the dimensionality of the correlations.

The classification of magnets now includes altermagnets which possess opposite-spin sublattices connected by rotation and share some features with ferro- and antiferromagnets. Here the authors report the anomalous Hall effect in Mn5Si3 and interpret the results in terms of a d-wave altermagnetic phase.

Interpretation of the physical phenomena observed in non-collinear antiferromagnets is challenging; imaging and writing magnetic domains is important for applications. Here the authors show magnetic domain imaging and writing in a non-collinear antiferromagnet by recording anomalous Nernst voltage in response to a localized thermal gradient.

The thermal and quantum fluctuations around a quantum critical point can be studied independently by mapping the evolution of the spin dynamics in the critical region of a dimerized quantum magnet using neutron scattering.

Exploring the helicity-orbital coupling induced skyrmion properties is essential for the spintronic applications. Here the authors report the current controlled skyrmions and antiskyrmions dynamics with locking-unlocking helicity in frustrated magnets by including the dipole-dipole interaction in their model.

Antiferromagnetism of the IrMn layer in Pt/IrMn/CoFeB/MgO/CoFeB three-terminal magnetic tunnel junctions can be electrically detected using tunnelling magnetoresistance and controlled by a spin–orbit torque generated by a 0.8 ns current pulse applied across the heavy-metal platinum layer.

Direct observation of ionic motion in buried metal/oxide interfaces and its correlation with physical properties is a challenging task. Here, the authors observe oxygen migration in a model system with controllable positive exchange bias, due to the redox-driven formation of a ferromagnetic interfacial layer.

Strongly correlated and topological phases of matter can be often described using the tools of quantum field theory. Here the authors report the thermal Hall effect in the antiferromagnetic skyrmion lattice of MnSc₂S₄, revealing transport features that can be attributed to an emergent SU(3) gauge field.

Efficient manipulation of magnetic order with electric current pulses is desirable for achieving fast spintronic devices and the Rashba-Edelstein effect provides a mean to achieve staggered spin-orbit torques. Here the authors show a generalized Rashba-Edelstein effect generating not only spin polarization but also orbital polarization.

Several recent experimental studies have found disconnected Fermi surface arcs emerging below the Neel temperature in several rare-earth mono-pnictides. While these electronic states have been attributed to a non-collinear antiferromagnetic order, experimental evidence of this has been lacking. Here Huang et al demonstrate the emergence of non-collinear antiferromagnetic order using spin-polarized scanning tunnelling microscopy.

The electric polarization of a multiferroic is reversed by the application and subsequent removal of a magnetic field, resulting in topologically protected unidirectional magnetoelectric switching.

The energy efficient control of magnetisation for memory applications is one of the most important challenges in the field of spintronics. The authors investigate theoretically the possibility of the switching a one-dimensional antiferromagnet using an external electric field.

Quantum degrees of freedom, such as spin or valleys, lie at the basis of many intriguing phenomena. In this theory work, the authors present a new type of spin-valley locking enabled by a crystalline symmetry, which allows for the generation of valley polarizations and net magnetization via strain, and non-collinear spin currents via charge currents.