Multivariable Scaling for the Anomalous Hall Effect

We derive a general scaling relation for the anomalous Hall effect in ferromagnetic metals involving multiple competing scattering mechanisms, described by a quadratic hypersurface in the space spanned by the partial resistivities. We also present experimental findings, which show strong deviation from previously found scaling forms when different scattering mechanism compete in strength but can be nicely explained by our theory

Evidence of the side jump mechanism in the anomalous Hall effect in paramagnets

Persistent confusion has existed between the intrinsic (Berry curvature) and the side jump mechanisms of anomalous Hall effect (AHE) in ferromagnets. We provide unambiguous identification of the side jump mechanism, in addition to the skew scattering contribution in epitaxial paramagnetic Ni$_{34}$Cu$_{66}$ thin films, in which the intrinsic contribution is by definition excluded. Furthermore, the temperature dependence of the AHE further reveals that the side jump mechanism is dominated by the elastic scattering

Silent diabetes mellitus, periodontitis, and a new case of thalamic abscess

Brain abscess is an unusual complication of uncontrolled diabetes. A solitary thalamic abscess is an uncommon type of brain abscess. We report a case of thalamic abscess, whereupon diabetes mellitus and periodontitis were diagnosed. The diagnosis and management of thalamic abscess, and the interplay of type 2 diabetes and periodontitis are discussed. A 56-year-old, Caucasian, man with no medical or travel history, presented with 5-day symptoms of meningeal irritation. Body mass index 30.6 kg/m2. CT demonstrated a solitary midline lesion with neoplasia as a differential diagnosis. It was biopsied and cultures grew Streptococcus milleri. He was treated by stereotactic puncture, external drainage and targeted intrathecal and systemic antibiotic therapy. HIV negative but glycated haemoglobin (HbA1c) 10.7% (93 mmol/mol). Dental examination revealed a small molar abscess. Radiological resolution of the thalamic abscess occurred within 2 months. Diabetes improved with 7 weeks of insulin, and maintained on metformin, HbA1c 6.9% (51 mmol/mol). There was no residual neurological disability

Infrared Imaging of Magnetic Octupole Domains in Non-collinear Antiferromagnets

Magnetic structure plays a pivotal role in the functionality of antiferromagnets (AFMs), which not only can be employed to encode digital data but also yields novel phenomena. Despite its growing significance, visualizing the antiferromagnetic domain structure remains a challenge, particularly for non-collinear AFMs. Currently, the observation of magnetic domains in non-collinear antiferromagnetic materials is feasible only in Mn$_{3}$Sn, underscoring the limitations of existing techniques that necessitate distinct methods for in-plane and out-of-plane magnetic domain imaging. In this study, we present a versatile method for imaging the antiferromagnetic domain structure in a series of non-collinear antiferromagnetic materials by utilizing the anomalous Ettingshausen effect (AEE), which resolves both the magnetic octupole moments parallel and perpendicular to the sample surface. Temperature modulation due to the AEE originating from different magnetic domains is measured by the lock-in thermography, revealing distinct behaviors of octupole domains in different antiferromagnets. This work delivers an efficient technique for the visualization of magnetic domains in non-collinear AFMs, which enables comprehensive study of the magnetization process at the microscopic level and paves the way for potential advancements in applications.Comment: National Science Review in pres

Spin colossal magnetoresistance in an antiferromagnetic insulator

Colossal magnetoresistance (CMR) refers to a large change in electrical conductivity induced by a magnetic field in the vicinity of a metal–insulator transition and has inspired extensive studies for decades1,2. Here we demonstrate an analogous spin effect near the Néel temperature, TN = 296 K, of the antiferromagnetic insulator Cr2O3. Using a yttrium iron garnet YIG/Cr2O3/Pt trilayer, we injected a spin current from the YIG into the Cr2O3 layer and collected, via the inverse spin Hall effect, the spin signal transmitted into the heavy metal Pt. We observed a two orders of magnitude difference in the transmitted spin current within 14 K of the Néel temperature. This transition between spin conducting and non-conducting states was also modulated by a magnetic field in isothermal conditions. This effect, which we term spin colossal magnetoresistance (SCMR), has the potential to simplify the design of fundamental spintronics components, for instance, by enabling the realization of spin-current switches or spin-current-based memories

High-Index Epitaxial Fe Films Grown on MgO(113)

The epitaxial growth of high-index Fe films on MgO(113) substrates is successfully achieved using direct current (DC) magnetron sputtering, despite the significant lattice constant mismatch between Fe and MgO. X-ray diffraction (XRD) analysis is employed to characterize the crystal structure of Fe films, revealing an Fe(103) out-of-plane orientation. Furthermore, our investigation reveals that the Fe[010] direction is parallel to the MgO[11¯0] direction within the films plane. These findings provide valuable insights into the growth of high-index epitaxial films on substrates with large lattice constant mismatch, thereby contributing to the advancement of research in this field

A global dataset of plant available and unavailable phosphorus in natural soils derived by Hedley method

Soil phosphorus (P) fractions are critical for understanding soil P dynamics and availability. This paper provides a global dataset of soil P fractions separated by the Hedley method. The dataset also includes key environmental factors associated with soil P dynamics and availability, including climate factors, vegetation, soil and parent material types, soil age, and soil physiochemical properties such as particle size, bulk density, pH in water, organic carbon, total nitrogen, and extractable iron and aluminium concentrations. This dataset includes measures of Hedley P fractions of 802 soil samples and was gathered through a literature survey of 99 published studies. Plant availability of each soil P fraction was noted. We anticipate that the global dataset will provide valuable information for studying soil P dynamics and availability, and it will be fused into earth system models to better predict how terrestrial ecosystems will respond to global environmental changes

Implementation analysis of transfer of development rights for conserving privately-owned built heritage in Hong Kong: A transaction costs perspective

Transfer of development rights (TDR) programs are introduced as an alternative institutional innovation to the traditional regulatory instruments for land development. They meet the demand for development and conservation while balancing the conflicts between public and private interests with minimal use of public funds. Most TDR literature is about nature conservation and there is little focus on the complicated process and diverse stakeholders’ interests of urban land use in dealing with built heritage conservation. Previous studies show that the success of TDR programs depends on various elements, especially policy design and implementation approaches. The design and implementation of TDR programs involves transaction costs that can reduce the efficiency and effectiveness of these programs. This paper aims at developing a framework for analyzing TDR programs. This proposed framework not only takes transactions costs into account, but also provides a basis for decision makers to decipher the process of informal TDR. Using Hong Kong as a case study, three TDR implementation modes are selected to examine how different informal institutional arrangements have resulted in specific transaction costs in practice and hindered TDR projects. Our findings, which are informed by transactions costs economics, provide practical insights in order to improving the efficiency and effectiveness of TDR programs, particularly in informal contexts

Nutrient Limitation on Ecosystem Productivity and Processes of Mature and Old-Growth Subtropical Forests in China

<div><p>Nitrogen (N) is considered the dominant limiting nutrient in temperate regions, while phosphorus (P) limitation frequently occurs in tropical regions, but in subtropical regions nutrient limitation is poorly understood. In this study, we investigated N and P contents and N:P ratios of foliage, forest floors, fine roots and mineral soils, and their relationships with community biomass, litterfall C, N and P productions, forest floor turnover rate, and microbial processes in eight mature and old-growth subtropical forests (stand age >80 yr) at Dinghushan Biosphere Reserve, China. Average N:P ratios (mass based) in foliage, litter (L) layer and mixture of fermentation and humus (F/H) layer, and fine roots were 28.3, 42.3, 32.0 and 32.7, respectively. These values are higher than the critical N:P ratios for P limitation proposed (16–20 for foliage, ca. 25 for forest floors). The markedly high N:P ratios were mainly attributed to the high N concentrations of these plant materials. Community biomass, litterfall C, N and P productions, forest floor turnover rate and microbial properties were more strongly related to measures of P than N and frequently negatively related to the N:P ratios, suggesting a significant role of P availability in determining ecosystem production and productivity and nutrient cycling at all the study sites except for one prescribed disturbed site where N availability may also be important. We propose that N enrichment is probably a significant driver of the potential P limitation in the study area. Low P parent material may also contribute to the potential P limitation. In general, our results provided strong evidence supporting a significant role for P availability, rather than N availability, in determining ecosystem primary productivity and ecosystem processes in subtropical forests of China.</p> </div