Topological magnetism features whirling spin textures protected by topology. Its effective control is of great significance for both fundamental research and device applications, yet achieved so far only in ferromagnetic systems. The inherent stability of antiferromagnetic analogues makes their control profoundly challenging. Here, through symmetry and model analysis, we demonstrate a novel ferroelectric switchable topological antiferromagnetism effect in two-dimensional multiferroics, i.e., the reversal of ferroelectric polarization is coupled to the switching of topology of antiferromagnetic spin texture─interconverting skyrmions and bimerons. The physics correlates to the polarization-dependent low-energy electronic states near the Fermi level, which modifies the single-ion anisotropy and thereby reconfigure antiferromagnetic topological spin order. We establish the design principles for the ferroelectric switchable topological antiferromagnetism. Followed by first-principles and atomistic spin model simulations, this effect is further demonstrated in AgCr2Te4/In2S3 heterobilayer. Our study opens a feasible approach toward precise control of topological antiferromagnetism.

Topological surface states (TSSs) are widely considered to facilitate electrochemical reactions that are critical to producing clean energy and combating climate change, but direct evidence of such novel topological catalysis remains elusive due to obscuration by coexisting topologically trivial bulk states and surface dangling bonds. Here, we resolve this conundrum via a close examination of topological crystalline insulators (TCIs) SnX (X = Te, S, or Se). Unlike topological insulators used in prevailing studies, TCIs possess mirror-symmetry-protected TSSs that can be tuned via breaking of crystal symmetry with minimal impact on topologically trivial bulk and dangling bond states, thereby isolating the effects of TSSs on catalysis. These results demonstrate TSSs as a decisive driver for hydrogen and oxygen evolution reactions, offering compelling evidence for the long speculated yet hitherto unconfirmed phenomenon of topological catalysis and identify TCIs as a material class for superior catalytic performance.

van der Waals magnets are attracting a great deal of attention for their potential integration into spintronic and magnonic technologies. CrSBr is an A-type antiferromagnet that shows a coupling between its electronic band structure and magnetic properties. This property is appealing for applications, and it also offers the possibility to investigate magnetic ground states and gigahertz magnons using visible optics techniques. Using Raman scattering and (magneto)-optical experiments, we describe the magnetic and optical properties of alloys of CrSBr1-xClx with x ⩽ 0.46. Similar to CrSBr, these alloys are direct band gap semiconductors with a coupling of their electronic and magnetic properties. Exciton energies evolve weakly with composition, and we describe the large changes in the saturation magnetic fields and their implications for the magnetic properties. We show that both the interlayer magnetic exchange and electronic interactions are modified by halogen mixing, offering the possibility to tune magnon energies with alloy composition.

Single-atom catalysts (SACs) promise maximum atomic utilization and enhanced intrinsic activity, yet their high surface energy results in thermal instability and sintering, hindering practical application. While lattice confinement stabilizes SACs, conventional 3D frameworks (e.g., MOFs) suffer from insulating behavior and inefficient pore-size control, compromising intrinsic catalytic efficiency. To overcome this, we introduce a novel lattice confinement paradigm using engineered two-dimensional porous monolayers. These hosts, designed via the "superatom" concept, possess intrinsic sub-nanometer pores that enforce a strong quantum confinement effect on anchored single atoms. We used first-principles calculations to screen 224 candidates, identifying stable hosts with diverse electronic properties. Evaluation of the hydrogen evolution reaction revealed superior catalytic performance over conventional doped architectures. This enhancement stems from the strong confinement effect, enabling precise, localized electronic control over the catalytic properties via active-site charge redistribution. Our work establishes a viable and electronically robust strategy for designing next-generation catalysts with tailored properties.

Flexible quantum-dot light-emitting diodes (QLEDs) based on silver-nanowires (AgNWs) transparent electrodes show great potential but suffer from surface roughness, poor wettability, and unstable interfaces. We propose a multifunctional interfacial engineering strategy using ZnMgO nanocrystals to address these issues. The ZnMgO layer acts as a nanoscale welding agent, preventing AgNWs sliding and improving mechanical stability while providing a smooth surface for uniform organic hole transport layer (HTL) deposition. As confirmed by capacitance-voltage (C-V) and single-carrier measurements, band alignment at the HTL/ZnMgO interface creates a low-barrier hole injection pathway, optimizing the charge balance. The resulting flexible QLED achieves 20.84% external quantum efficiency (EQE), 43,270 cd/m2 luminance, and excellent voltage tolerance, with brightness stable up to 10.8 V. The device retains over 80% performance after 2000 bending cycles. Moreover, this strategy achieves up to 27.52% EQE for flexible QLEDs based on conventional electrodes, indicating a scalable route for optoelectronics.

Deterministic placement of single dopants is essential for scalable quantum devices based on Group V donors in silicon. We demonstrate a nondestructive, high-efficiency method for detecting individual ion implantation events using secondary electrons (SEs) in a focused-ion-beam system. Using low-energy Sb ions implanted into undoped silicon, we achieve up to 98 ± 1% single-ion detection efficiency (DE). We find that introducing thin, controlled SiO2 capping layers enhances the SE yield, consistent with the increased electron mean-free path in the oxide, while maintaining successful ion deposition in the underlying silicon substrate. Our approach provides a robust and scalable route to precise donor placement and extends deterministic implantation strategies to a broad range of material systems and quantum device architectures.

The development of reversible metal anodes is a key challenge for advancing aqueous battery technologies, particularly for scalable and safe stationary energy storage applications. Here we demonstrate a strategy to realize epitaxial electrodeposition of iron (Fe) on single-crystal copper (Cu) substrates in aqueous electrolytes. We compare the electrodeposition behavior of Fe on polycrystalline and single-crystalline Cu substrates, revealing that the latter enables highly uniform, dense, and crystallographically aligned Fe growth. Comprehensive electron backscatter diffraction and X-ray diffraction analyses confirm the formation of Fe with specific out-of-plane and in-plane orientations, including well-defined rotational variants. Our findings highlight that epitaxial electrodeposition of Fe can suppress dendritic growth and significantly enhance the Coulombic efficiency during plating/stripping cycles. This approach bridges fundamental crystallography with practical electrochemical performance, providing a pathway toward high-efficiency aqueous batteries utilizing Earth-abundant materials.

Integrating tunable leaky-integrate-and-fire (LIF) dynamics with a synaptic memristor holds profound promise in the early diagnosis of neurological disorders. Here, a SnNb2O6-based capacitive memristor is presented, which emulates a biosynaptic neuron through an LIF-type excitatory postsynaptic current (EPSC) for epileptic seizure monitoring. The device functions with stable coupled bipolar switching and capacitive response under both DC and pulsed operation over 500 consecutive cycles; in particular, single-pulse stimulus triggers a highly reproducible LIF-type three-stage EPSC feature. Various stimulation protocols enable diverse synaptic behaviors, and the device response can transition from transient to persistent states by tuning readout-delay. Mechanistic analysis attributes the capacitive memristor behavior to the coupling effect between interfacial polarization/displacement current and dynamic Schottky barrier modulation. By employing measured LIF-type EPSC as convolution kernels for raw electroencephalogram (EEG) signals in a lightweight one-dimensional convolutional neural network (1D-CNN), a 95.8% classification accuracy for three epilepsy-related states is achieved on the Bonn dataset. The results highlight the potential of the capacitive memristor for on-chip epileptic seizure monitoring.