Despite advances in single-atom doping, the controlled assembly of multi-atom defects in 2D materials remains difficult, limiting the ability to tailor their electronic, magnetic, or catalytic functionality. Here, we demonstrate that ultralow-energy (82 eV) implantation of mass-selected Mn2 cluster ions into monolayer graphene enables the formation of substitutional Mn dimers. Low-temperature scanning tunneling microscopy and spectroscopy, supported by density-functional theory calculations, reveal that these Mn–Mn pairs exhibit a characteristic four-lobe signature and distinct spectroscopic fingerprints. Molecular dynamics simulations show that Mn2 dimers fragment upon impact, displacing several carbon atoms and enabling recombination events that yield substitutional dimers. These results show that cluster-ion implantation can create multi-atom defects in 2D materials, extending ultralow-energy implantation beyond single-atom doping. This provides access to a broader range of defects relevant to spintronics, quantum technologies, and catalysis.

Extremely large magnetoresistance (XMR) observed in topological materials holds significant promise for spintronic applications. In this work, we systematically investigate the magnetotransport properties and quantum oscillations in high-quality single crystals of the magnetic nodal-line semimetal FeGe2. Synthesized via chemical vapor transport, the FeGe2 crystals exhibit an exceptional residual resistivity ratio of 533 and achieve a nonsaturating XMR of 23 000% at 1.8 K and 14 T, accompanied by ultrahigh carrier mobility (1 x 105 cm2 V-1 s-1). Shubnikov-de Haas oscillations reveal a pi-Berry phase, suggesting a possible nontrivial topological nature of FeGe2. The remarkably high ratio of transport-to-quantum lifetimes (tau tr/tau Q approximate to 1571) further confirms suppression of backscattering, possibly related to topological protection. Combined with Hall effect measurements and extended Kohler scaling analysis, we establish that the origin of XMR in FeGe2 arises from the synergistic interplay between topological protection and high carrier mobility, rather than conventional electron-hole compensation. These findings not only provide critical experimental insights into the XMR mechanism of magnetic nodal-line semimetals but also highlight FeGe2 as a promising candidate for designing next-generation topological spintronic devices.

The physics at antiferromagnetic (AFM)/ferromagnetic (FM) interfaces, including exchange bias (EB) and spin current, are of key interest in spintronics. However, the relationship between the EB effect and spin current is still controversial. Here, we have observed anisotropic and controllable nonlocal damping in a typical EB system, i.e., Co/CoO bilayers. Oblique deposition of Co film with an in situ oxidized CoO top layer generates a controllable uniaxial magnetic anisotropy (UMA), and leads to reconfigurable orientations of the average interfacial uncompensated AFM spins. The Gilbert damping constant is larger in the hard axis than in the easy axis of UMA, which can be further enhanced by the training effect because of the reorientation of the average uncompensated AFM spins. Our work provides insight into the effect of EB on nonlocal damping and paves a new way to control the spin current in AFM spintronic devices.

The coexistence of topological bands around the Fermi level (E_{F}) and superconductivity provides a fundamental platform for exploring their interplay. However, few materials inherently display both properties. In this Letter, we demonstrate the coexistence of topological surface states at the E_{F} and superconductivity in NiTe_{2} single crystals, a material hitherto not recognized as superconducting. Quasiparticle interference measurements performed via scanning tunneling microscopy suggest the presence of topological surface states at the E_{F}, which is further corroborated by density functional theory simulations. Experimental evidence for superconductivity is provided via electronic transport measurements and specific heat capacity analyses. Our results suggest that NiTe_{2} represents a promising platform for investigating the rich interplay between topological states and superconductivity.

We have systematically studied the electromagnetic transport properties of PbTe thin films under gate voltage modulation. The system demonstrates pronounced electron-electron interactions exclusively within the gate voltage range where only hole carriers are present. Furthermore, the Berry phase is utilized to qualitatively elucidate the transition between weak antilocalization (WAL) and weak localization (WL) through the regulation of gate voltage and temperature. Using the three-resistor model, we have effectively explained the correlation between the characteristic temperature of the R-T curve, the coexistence of electron-hole carriers, and the nonmonotonic temperature dependence of negative magnetoresistance (NMR), consistently indicating that complex magnetotransport phenomena are caused by microscopic disorder. Our research findings open up new avenues for exploring and manipulating the magnetotransport properties of PbTe thin films.

Extremely large magnetoresistance (XMR) is typically observed in topological materials as associated with factors such as high mobility carriers and electron-hole compensation. However, its occurrence in magnetic materials is rather rare due to the stability of the electron spin in magnetic fields. In this study, the synthesis of high-quality single crystals of Fe2Ge3 with the highest residual resistivity ratio (RRR = 4778) has allowed to explore its intrinsic magnetic and electrical transport properties, revealing a narrow-gap semiconductor nature with a high XMR of 2057% at 1.8 K and 12 T. In addition, Fe2Ge3 is able to bridge the gap between magnetism and XMR. These findings not only advance our understanding of Fe2Ge3, but also open avenues for the development of spintronic devices and other technologies based on magnetic semiconductors.

Porous particles are crucial in environmental engineering, energy, and the chemical industry, boasting unique hierarchical structures and extensive surface areas. This review delves into their structural characteristics and flow-transfer properties, with a focus on how innovations like 3D printing enhance our understanding of these elements. Research primarily utilizes numerical simulations, particularly microscale methods such as pore network and direct pore-scale models, to provide detailed insights. However, linking these findings to reactor-scale applications remains a challenge, highlighting the need for advanced multiscale modeling and integration of experimental techniques to improve designs. This variability in flow and transfer properties at different porous structure significantly affects their practical efficiency. The review advocates for optimized pore design to enhance heat and mass transfer, aiming to develop models that encompass hierarchical structures and explore integrated flow-transfer-reaction mechanisms, ultimately enhancing the utility of porous particles in key engineering fields.

Recently, theoretical and experimental research predicted that ferromagnets with strong spin-orbit coupling (SOC) could serve as spin sources with dramatically enhanced spin-orbit torque (SOT) efficiency due to the combination of spin Hall effect and anomalous Hall effect (AHE), presenting potential advantages over conventional nonmagnetic heavy metals. However, materials with a strong SOC and room-temperature ferromagnetism are rare. Here, we report on a ferromagnetic (FM) interfacial phase with Curie temperature exceeding 300 K in the heavy transition-metal oxide CaRuO3, in proximity to La0.67Sr0.33MnO3. Electron energy loss and polarized neutron reflectometry spectra reveal the strong charge transfer from Ru to Mn at the interface, triggering antiferromagnetic exchange interactions between interfacial Ru/Mn ions and thus transferring magnetic order from La0.67Sr0.33MnO3 to CaRuO3. An obvious advantage of such interfacial phase is the enhanced anomalous Hall effect at temperatures from 150 to 300 K. Compared to the most promising room-temperature ferromagnetic oxide La0.67Sr0.33MnO3, the anomalous Hall conductivity σxyAHE (or anomalous Hall angle θH) of CaRuO3/La0.67Sr0.33MnO3 superlattices is increased by 30 (or 31) times at 150 K and 10 (or 3) times at 300 K. This work demonstrates a special approach for inducing ferromagnetism in heavy transition-metal oxides with strong SOC, offering promising prospects for all-oxide-based spintronic applications.

The interaction of defects has been proven effective in regulating the mechanical properties of structural materials, while its influence on the physicochemical performance of functional materials has been rarely reported. Herein, we synthesized Ag nanorods with dense stacking faults and investigated how the defect interaction affects the catalytic properties. We found that the stacking faults can couple with each other to form a unique structure of opposite atoms with extortionately high tensile strain. Experimental and theoretical analyses reveal that the opposite-atom structure facilitates the adsorption and activation of CO2 molecules, thus improving the catalytic performance of the carbon dioxide electroreduction reaction (CO2RR). As a result, Ag nanorods achieve high CO partial current density (-11.87 mA cm-2 at -0.8 V vs RHE) and high Faraday efficiency (>95%), superior to most Ag-based catalysts. Our work indicates that the defect interaction is an effective means to boost the performance of functional materials.

Quantitative understanding of the chemisorption on single-atom catalysts (SACs) by their electronic properties is crucial for the catalyst design. However, the physical mechanism is still under debate. Here, the CO catalytic oxidation on single transition metal (i.e., Sc, Ti, V, Cr, Mn, Fe, Co, Ni) dopants is used as a theoretical model to explore the correlations between the characteristics of electronic structures and the chemisorption on SACs. For these metal dopants, their atomic d orbitals form several nondegenerate and localized electronic states that are found to be selectively coupled with the π* orbital of the adsorbed O2, which we defined as selective orbital coupling. Based on the selective orbital coupling, we find that the alignment between the selected d state and the π* state determines the bond strength, regardless of the electron occupation number of the selected d states; the electron transfer to form M-O bonding can be provided by the support. Such electron transfer can be related with the electronic metal-support interaction. We attribute the origin of the chemisorption mechanism to the coexistence of the localized orbital of the single transition metal and the continuous energy band of the Au support. Finally, we illustrate how this mechanism dominates the variation trend of the reaction barriers. Our results unravel a fundamental adsorption mechanism in SAC systems.

Exploring one-dimensional (1D) ferromagnetic chains with high magnetic transition temperatures and robust spin polarization is crucial for the development of next-generation spintronic devices. Here, we demonstrate a bottom-up approach to the design and assembly of a 1D ferromagnetic chain based on the magic sandwich cluster Ho2B8. The stability of Ho2B8 is rationalized by the large HOMO-LUMO gap (2.02 eV) and double sigma + pi aromaticity. Our results show that the 1D linear chain is an attractive ferromagnetic semiconductor with the valence band fully spin-polarized. The long-range ferromagnetic order with a 5 mu B magnetization on each Ho atom retains up to 86 K, and it features a magnetic transition within a tiny compressive strain (5%). Furthermore, the 1D linear chain exhibits a sizable magnetic anisotropy energy up to 30 meV/atom, indicating a sufficient energy barrier to suppress the spin fluctuations. The present findings suggest that the magnetic lanthanide chain (Ho2B8)n is a prospective candidate for next-generation spintronic devices.

The lack of effective and non-corrosive hole-transporting layer (HTL) materials has remained a long-standing issue that severely restricts the performance of organic solar cells (OSCs). Most pH-neutral conjugated polyelectrolytes (CPEs) exhibit inferior performance to the acid-doped HTL materials due to their low doping density. In this study, a series of pH-neutral CPEs is designed and synthesized with high doping density as HTL materials. Through an elaborate synthetic route, two sulfonate-terminating alkoxyl side chains can be introduced into thiophene, by which the electron-rich, highly soluble, and chemically stable thiophene monomer is synthesized to enable the subsequent polymerization. The CPE PTT-F exhibit a remarkable self-doping property with an enhanced doping density from 2.01 × 1017 to 7.02 × 1018 cm-3. The high work function and the increased doping density of PTT-F-based HTL decrease the depletion region width from 38.4 to 8.1 nm at the anode interface, which minimized the energy loss in hole transport. Consequently, a binary OSC modified by PTT-F-based HTL achieve a high PCE of 18.8%. To the best of the knowledge, this is the highest PCE for OSC employing CPE-based HTL. The results from this work demonstrate an encouraging achievement of realizing exceptional hole collection ability in pH-neutral CPEs.

Manipulating point defects for tailored macroscopic properties remains a formidable challenge in materials science. This study demonstrates a proof-of-principle for a universal law involving element Mn, significantly enhancing vacancy diffusion through an unprecedented anomalous Friedel Oscillations phenomenon, across most metals in the periodic table. The correlation between Mn-induced point-defect dynamic changes and intrinsic macro-properties is robustly validated through the first-principles theory and well-designed experiments. The physical origin stems from Mn's exceptionally large effective intra-elemental 3d electron interactions, surpassing the Coulomb attraction induced by vacancy and disrupting the electron screening effect. Given the ubiquitous nature of vacancies and their recognition as the most crucial defects influencing nearly all physical and mechanical properties of crystalline materials, this outcome may drive advances in a broad domain.

Knowledge Distillation (KD) uses the teacher's logits as soft labels to guide the student, while self-KD does not need a real teacher to require the soft labels. This work unifies the formulations of the two tasks by decomposing and reorganizing the generic KD loss into a Normalized KD (NKD) loss and customized soft labels for both target class (image's category) and non-target classes named Universal Self-KD (USKD). We decompose the KD loss and find the non-target loss from it forces the student's non-target logits to match the teacher's, but the sum of the two nontarget logits is different, preventing them from being identical. NKD normalizes the non-target logits to equalize their sum. It can be generally used for KD and self-KD to better use the soft labels for distillation. USKD generates customized soft labels for both target and non-target classes without a teacher. It smooths the target logit of the student as the soft target label and uses the rank of the intermediate feature to generate the soft non-target labels with Zipf's law. For KD with teachers, NKD achieves state-of-the-art performance on CIFAR-100 and ImageNet, boosting the ImageNet Top- 1 accuracy of Res-18 from 69.90% to 71.96% with a Res-34 teacher. For self-KD without teachers, USKD is the first method that can be effectively applied to both CNN and ViT models with negligible additional time and memory cost, resulting in new state-of-the-art results, such as 1.17% and 0.55% accuracy gains on ImageNet for MobileNet and DeiT-Tiny, respectively. Code is available at https://github.com/yzd-v/cls_KD.

One-dimensional (1D) atomic chains that exhibit large magnetic anisotropy are highly relevant to spintronic applications. Such 1D magnetic systems have usually been produced by atom/molecular assembling on solid surfaces or by coordination polymers. Here, we demonstrate an alternative approach for the formation of a confined ferromagnetic holmium (Ho) atom chain, which is composed of repeating units of the tubular Ho doped boron (B) cluster HoB20. The tubular HoB20 is discovered by the global structural search of a series of small-sized boron clusters doped by a single Ho atom (HoBn, n = 12, 14, 16, 18, 20) using ab initio calculations. Electronic analysis reveals that the individual HoB20 cluster is stabilized by the double sigma + pi aromaticity. Extending the tubular structure results in a single Ho atom chain being confined inside a boron nanotube, which shows ferromagnetic behaviors and a large magnetic anisotropy of more than 40 meV/atom. Our findings indicate that the magnetic lanthanide chain is a promising candidate for high-density magnetic information storage.

High‐quality single crystals with length up to 6 mm are successfully grown by the physical vapor transport (PVT) technique. The crystals exhibit unique tubular structures with a hexagonal cross section. The high‐quality crystal is studied by a series of structural and morphological characterization. The physical properties including both magnetization and electrical transport are studied in detail. It is found that there exists a coexistence of weak ferromagnetism and antiferromagnetism at low temperatures. In the measured temperature range of 2–300 K, shows a typical metallic behavior, and the temperature dependence of the resistivity ρ x x ( T ) can be well fitted by the parallel‐resistor model.

Individual magnetic transition metal dopants in a solid host usually exhibit relatively small spin excitation energies of a few meV. Using scanning tunneling microscopy and inelastic electron tunneling spectroscopy (IETS) techniques, we have observed a high spin excitation energy around 36 meV for an individual Co substitutional dopant in ultrathin NaCl films. In contrast, the Cr dopant in the NaCl film shows much lower spin excitation energy around 2.5 meV. Electronic multiplet calculations combined with first-principles calculations confirm the spin excitation induced IETS, and quantitatively reveal the out-of-plane magnetic anisotropies for both Co and Cr. They also allow reproducing the experimentally observed redshift in the spin excitations of Co dimers and ascribe it to a charge and geometry redistribution.

Interface optimization has been widely used to improve the optoelectronic properties of nanocomposites, but the theoretical estimation of their effect on the interfacial carrier transfer dynamics is insufficient. Therefore, it is very significant to explore the introduced interface electronic structural state and corresponding interfacial electron transfer behavior. In this paper, the possible electron transition path in l-cysteine (l-Cys) sensitized C3N4/CoP (R-C3N4/CoP) and contrast C3N4/CoP is explored, and the corresponding electron transition probability of these paths is calculated by the transition dipole moment. As a result, due to the introduction of l-Cys, the electron transition probability of R-C3N4/CoP is one order of magnitude higher than that of other path without l-Cys. Moreover, these theoretical calculation results are in good agreement with our experimental results.

The free-standing Au-20 cluster has a unique tetrahedral shape and a large HOMO-LUMO (highest occupied molecular orbital-lowest unoccupied molecular orbital) gap of around 1.8 electron volts. The "magic" Au-20 has been intensively used as a model system for understanding the catalytic and optical properties of gold nanoclusters. However, direct real-space ground-state characterization at the atomic scale is still lacking, and obtaining fundamental information about the corresponding structural, electronic, and dynamical properties, is challenging. Here, using cluster-beam deposition and low-temperature scanning tunneling microscopy, atom-resolved topographic images and electronic spectra of supported Au-20 clusters are obtained. We demonstrate that individual size-selected Au-20 on ultrathin NaCl films maintains its pyramidal structure and large HOMO-LUMO gap. At higher cluster coverages, we find sintering of the clusters via Smoluchowski ripening to Au-20n agglomerates. The evolution of the electron density of states deduced from the spectra reveals gap reduction with increasing agglomerate size.