High contact resistance induced by low quantum tunneling probability (TP) limits the performance of 2D electronic devices, making the modulation of Schottky barrier height (SBH) and contact types crucial. van der Waals heterostructures (vdWHs) composed of 2D transition metal carbides (MXenes) and metallic transition metal dichalcogenides (TMDs) serve as an ideal platform for exploring the interface contact physics in high-performance 2D devices. Via first-principles calculations, this study systematically investigates the geometric structures, stability, and electronic properties of nine XY2/Sc2CCl2 (X = Nb, Ni, Ti, V, Mn, Ta; Y = S, Se) vdWHs. The contact characteristics of these vdWHs were explored using three modulation strategies: semiconductor layer number, vertical electric field, and vertical strain. All vdWHs exhibit good thermodynamic, dynamic, and thermal stability. Except for TiS2/Sc2CCl2, which forms a p-type Schottky contact, the other eight vdWHs form n-type Schottky contacts, with their SBH dominated by the metal work function. In the intrinsic state, all vdWHs show low TP (2.67-4.87%), indicating high contact resistance. The three modulation strategies are effective: increasing the number of Sc2CCl2 layers raises SBH and reduces TP; a vertical external electric field induces reversible Schottky-Ohmic transitions (the critical field is related to the metal work function); vertical strain modulates barrier width/height via interlayer coupling, and compressive strain boosts the TP to nearly 100%. This work elucidates the modulation mechanisms of 2D metal-semiconductor interfaces, providing a theoretical basis and design strategies for low-contact-resistance, high-performance 2D electronic devices.

The dynamic magnetoelectric (ME) effect of the scheelite-type DyCrO4 has been investigated by measurements of the temperature and magnetic field dependence of the dynamic magnetoelectric coefficient (αE = dE/dH). A high dynamic ME coefficient αE is obtained in the multiferroic phase after a poling process under both electric and magnetic fields. The maximum of αE appears at the critical field of a metamagnetic transition where spin fluctuation becomes the most significant. The dynamic ME effect for H ⊥ E is much stronger than that for H ∥ E, consistent with the spin current model. Moreover, the sign of αE is reversed when the direction of electric polarization is reversed by a negative electric field. Therefore, the state of αE can be used to store information in single-phase multiferroics.

Abstract This paper presents a monolithic high-temperature superconducting (HTS) K-band sub-harmonic Josephson mixer using a pair of reverse-biased Josephson junctions, which are biased using reversed DC current. The sub-harmoic mixer can provide higher conversion gain and stronger rejection of the even-order harmonics of the LO signal. A matching circuit with several bandpass filters is designed to match the junctions and achieve a maximum conversion gain. Based on the circuit configuration and using the established Verilog-A Josephson junction mixer model, transient simulation has been done in the circuit simulator. An electromagnetic model is built and simulated in full-wave simulation environment, and the results reveal that the design realizes very low loss at 25 GHz, excellent port isolation and high conversion efficiency. A prototype has been fabricated and tested in a cryocooler at operating temperatures of 40 K and 20 K. Measurements have experimentally verified the novel RF design and simulation results. Maximum conversion gains of -10.5 dB and -6.5 dB were obtained at 40 K and 20 K, respectively, with a bandwidth greater than 400 MHz and outstanding gain linearity. It is also predicted that the mixer performance can be further improved with higher critical current Ic values and identical or similar Ic values between two parallel junctions.

The Risk of Bias in Vaccine Effectiveness (RoB-VE) project: introduction to a methodological initiative to improve risk-of-bias assessment and reporting in vaccine effectiveness research.

β-Ga2O3 is promising for power and solar-blind UV photodetection due to its wide bandgap, high critical field, and ease of n-type doping with Si. However, a doping limit arises at high Si concentrations, attributed to band-gap narrowing and renormalization caused by dopants and defects. Dopant ionization (via the Franz-Keldysh effect) and defects (via the Urbach effect) both induce band-gap narrowing and alter the absorption coefficient, yet their individual contributions are difficult to decouple from absorption spectra near the bandgap (4.5-5 eV). This study extends analysis to 2-5 eV using machine learning, enabling the separation of each effect's contribution. The resulting metric directly reflects changes induced by doping. This unreported finding clarifies the intrinsic band-gap narrowing mechanism in Si-doped β-Ga2O3 and offers valuable guidance for other n-type doping studies.

Monitoring and warning of ppmv-level fault-free humidity upper limit (ppmv-FFHUL) are crucial for ensuring system reliability in critical fields such as high-tech manufacturing, and aerospace. However, existing ppmv-FFHUL warning technologies are scarce, and constrained by "gradual change" response modes, resulting in complicated equipment, high costs, and insufficient portability, which greatly limits their flexible application. To address this, we propose a "leap change" response mode and an "enzyme-like" construction method for precise ppmv-level humidity threshold modulation. It is achieved through synergistic supramolecular interactions between two size-matched auxiliary mediums to precisely construct an "enzyme like" microenvironment containing a matching number of multi-level, spatially fixed sensitizing functional groups around an elaborately designed humidity-sensitive component. The as-prepared material combines paper-like flexibility, facile fabrication and handling, and enables high-contrast readout of the target ppmv-FFHUL only by naked-eye. Moreover, it holds promise as an easily deployable ppmv-FFHUL warning labels and provide a visual pre-alert signal 20% ahead of the critical value. It offers a portable and low-cost solution for specialized scenarios that require early warning and rapid screening of ppmv-level humidity. Furthermore, the "enzyme-like" precise construction method and the "leap change" response mode provide an innovative perspective for the design of other high-performance trace-level monitoring materials.

Multifractality in critical neural field dynamics

This study investigates the interplay between superconductivity and topological surface states in heterostructures formed by combining the well-known three-dimensional topological insulator Sb2Te3 with the iron chalcogenide superconductor FeSe0.5Te0.5, which is characterized by its simple crystal structure and high critical field. Remarkably, even with a certain lattice mismatch between Sb2Te3 and FeSe0.5Te0.5, superconductivity is successfully induced on the surface of Sb2Te3 film, as demonstrated by the observation of a zero-resistance state. Based on this observation, we conducted a detailed investigation into the impact of Sb2Te3 film thickness on superconductivity in these heterostructures. Our results show that the superconducting transition temperature (Tc) decreases as the Sb2Te3 film thickness increases, yet remains unexpectedly high, even for films as thick as about 670 nm. This suggests that the long-range superconducting proximity effects in Sb2Te3 films are likely due to the topological surface states, which possess long mean free paths. The Sb2Se3/FeSe0.5Te0.5 heterostructure formed using Sb2Se3 without topological surface states, along with angle-resolved photoemission spectroscopy of Sb2Te3/FeSe0.5Te0.5, further suggested the possible coexistence of topological surface states and superconductivity in the Sb2Te3/FeSe0.5Te0.5 heterostructure. These findings offer an excellent platform for exploring the properties of topological superconductivity and detecting Majorana fermions.

The growing demand for electric vehicles, renewable energy systems, and portable electronics has led to the widespread adoption of power conversion systems. Although advanced structures like the superjunction MOSFET have prolonged the viability of silicon in power applications, maintaining its dominance through cost efficiency, Si-based technology is ultimately constrained by its intrinsic limitations in critical electric fields. To address these constraints, research into wide bandgap semiconductors aims to minimize system footprint while maximizing efficiency. This study reviews the semiconductor landscape, demonstrating why Gallium Nitride (GaN) has emerged as the most promising technology for next-generation power applications. With a critical electric field of 3.75MV/cm (12.5× higher than Si), GaN facilitates power devices with lower conduction loss and higher frequency capability when compared to their Si counterpart. Furthermore, this paper surveys the GaN ecosystem, ranging from device modeling and packaging to monolithic ICs and switching converter implementations based on discrete transistors. While existing literature primarily focuses on discrete devices, this work addresses the critical gap regarding GaN monolithic integration. It synthesizes key challenges and achievements in the design of GaN integrated circuits, providing a comprehensive review that spans semiconductor technology, monolithic circuit architectures, and system-level applications. Reported data demonstrate monolithic stages reaching 30mΩ and 25MHz, exceeding Si performance limits. Additionally, the study reports on high-density hybrid implementations, such as a space-grade POL converter achieving 123.3kW/L with 90.9% efficiency.

In contemporary society, developing more efficient information processing systems has become a critical goal in modern technological advancement. Among emerging technologies, neuromorphic devices, benefiting from their in-memory computing characteristics, hold significant potential to become a breakthrough technology for overcoming current computational bottlenecks. The key to realizing brain-inspired computing lies in the hardware foundation, specifically, neuromorphic devices capable of simulating biological neuron and synapse functions. In recent years, two-dimensional nanomaterials, represented by graphene, transition metal dichalcogenides, and black phosphorus, have emerged as promising materials for neuromorphic devices due to their excellent optoelectronic properties, tunable electrical states, and operational principles that closely resemble those of biological synapses and neurons. By reviewing recent research progress in this field, this article focuses on the applications and challenges of two-dimensional nanomaterials in neuromorphic devices. However, transitioning this technology from the laboratory to large-scale applications still faces multiple challenges, including fabrication processes, integration strategies, and synergistic algorithm architectures. Future advancements will depend on the exploration of new material systems, breakthroughs in three-dimensional heterogeneous integration technologies, and genuine hardware-algorithm co-design. Ultimately, these efforts will drive transformative applications of two-dimensional material-based neuromorphic chips in critical fields such as edge intelligence and biomimetic sensing.

Purpose This paper argues for greater intentionality in the design of field trips within K-12 education, particularly in urging attention to cultural responsiveness and anti-bias curriculum. Such experiences deepen student learning, support and affirm identity, and promote empathy. Design/methodology/approach Drawing from experiential learning theory and anti-bias education, the paper focuses on the critical field trip phases of preparation and reflection. Further introduced are strategies to mediate field trips themselves, focusing on inclusive curriculum design, teacher-site collaboration and alternative technologies, such as virtual exchanges. Findings The paper concludes that culturally responsive field trips can shift from isolated enrichment activities to transformative educational experiences that improve academic outcomes and foster lifelong critical thinking habits. Such experiences are most effective when motivated by sustained engagement. Research limitations/implications The paper integrates a wide body of research; empirical findings are not otherwise presented. However, the paper identifies future research directions, from teacher preparation to the long-term impacts of experiential learning on student development. Practical implications Models discussed here may be readily implemented by educators, particularly around anti-bias standards. Practical recommendations range from partnering more closely with inclusive institutions to developing pre- and post-visit activities. The paper also expands on alternative field trip models, including virtual (global) and hyperlocal experiences. Originality/value Collaborative commitments between social studies teachers and site-based staff can lead to a transformative – and more continuous – experience.

Aluminum (Al) has attracted considerable attention for uses in photonic, electronic, and quantum devices. Its grain architecture governs surface roughness, electron and light scattering, and quantum decoherence, all of which critically affect device performance. Enhancing crystalline domain size and refining granularity control remain an ongoing research focus for producing ultraclean nanofilms. This study investigates the crystallinity of epitaxial Al grown on miscut GaAs substrates and examines its influence on Al superconductivity. The introduction of a substrate miscut alters Al growth kinetics, enabling the formation of twinned grains, polycrystalline structures, and micrometer-scale single crystal. Variations in grain architecture result in approximately 10%, 100%, and 1000% modulation of the superconducting critical temperature, current, and magnetic field, respectively, while maintaining constant channel geometries. Reducing macroscopic grain boundaries decreases the Al nanofilm resistivity but enhances strain-induced crystallinity deterioration, driving a transition from type-I to type-II-like superconducting behavior. We suggest that preparing Al nanofilms, which approach an ultraclean limit in terms of surface quality, crystallinity, and transport properties, requires careful control of substrate miscut as well as the grain architecture. These findings highlight a tunable approach to controlling Al granularity and superconductivity via miscut, lattice-mismatched substrates.

In the post-Moore era, next-generation optoelectronics and neuromorphic computing systems require ultrawide bandgap semiconductors with tunable properties. β-Ga2O3 stands as a promising candidate, possessing a bandgap of 4.5-4.9 eV and a high critical electric field of ∼ 8 MV/cm. However, its practical application is hindered by difficulties in synthesizing high-quality 2D forms and optimizing metal-semiconductor contacts. In this study, highly crystalline ultrathin 2D β-Ga2O3 nanoflakes with improved interface quality and enhanced carrier transport dynamics were synthesized using a space-confined CVD approach. The nanoflakes exhibit excellent structural and crystalline quality, as evidenced by the characteristic peaks in Raman spectroscopy and XRD, along with the clear lattice structure observed via TEM. Metal-semiconductor-metal devices with Ti-Ti, Pd-Pd, and Ti-Pd electrode configurations were fabricated and evaluated through current-voltage and time-resolved current-time measurements. The results reveal that the Schottky barrier height at the metal-Ga2O3 interface plays a decisive role in device performance. Notably, the Ti-Ti device exhibited a distinctive two-stage photocurrent decay after light illumination ceased, attributed to defect-mediated trapping and release of photogenerated carriers. By incorporating this unique photoresponse behavior into a deep neural network, promising image recognition accuracy was achieved on the Modified National Institute of Standards and Technology data set. This work not only offers a reliable pathway for synthesizing high-quality 2D β-Ga2O3 but also demonstrates its potential for application in high-performance optoelectronics and neuromorphic computing.

Professions such as military, aviation, submarine operation, and emergency response require individuals to navigate complex environments characterized by limited information, stringent time constraints, and significant pressures. Effective decision making under pressure is crucial in safety–critical professions, yet measuring this expertise remains challenging. Inspired by the military context, this article introduces the virtual reality decision-making expertise (VR-DMX) environment, designed to evaluate decision-making expertise under time constraints within a virtual reality scenario. VR-DMX simulates an amusement arcade where users must decide how to allocate time across various games to maximize ticket earnings. Through two validation studies (N = 60 and N = 76), we examined two metrics: Total Tickets (measuring overall performance) and DMX score (isolating decision-making quality). Both metrics demonstrated symmetrical distributions without floor or ceiling effects, with coefficients of variation comparable to established individual difference measures (32.4–37.4% for Total Tickets; 20.8–27.6% for DMX score). The moderate correlation between metrics (meta-analysis r = 0.771, 95% CI [0.599, 0.943]) indicates they measure related but distinct constructs. Our findings indicate that VR-DMX effectively differentiates individual performance levels and captures a distinct decision-making component that is separate from general cognitive abilities. Comparing decision-making expertise between professionals in safety–critical fields with those without such experience would be a sensible next step to help validate the potential for selection and training applications. VR-DMX was designed to measure decision-making expertise in safety–critical contexts, and initial validation data demonstrating effective differentiation of individual performance levels suggest that continued development could fulfill this design intention for applications in selection, training, and performance prediction.Supplementary InformationThe online version contains supplementary material available at 10.1186/s41235-025-00695-6.

In cuprate high-temperature superconductors the doping level is fixed during synthesis, hence the charge carrier density per CuO2 plane cannot be easily tuned by conventional gating, unlike in 2D materials. Strain engineering has recently emerged as a powerful tuning knob for manipulating the properties of cuprates, in particular charge and spin orders, and their delicate interplay with superconductivity. In thin films, additional tunability can be introduced by the substrate surface morphology, particularly nanofacets formed by substrate surface reconstruction. Here we show a remarkable enhancement of the superconducting onset temperature {T}_{{{{rm{c}}}}}^{{{{rm{on}}}}} and the upper critical magnetic field Hc,2 in nanometer-thin YBa2Cu3O7−δ films grown on a substrate with a nanofaceted surface. We theoretically show that the enhancement is driven by electronic nematicity and unidirectional charge density waves, where both elements are captured by an additional effective potential at the interface between the film and the uniquely textured substrate. Our findings show a new paradigm in which substrate engineering can effectively enhance the superconducting properties of cuprates. This approach opens an exciting frontier in the design and optimization of high-performance superconducting materials.

Oxygen vacancies (Ov) on metal oxide surfaces exhibit high catalytic activity for activating peroxymonosulfate (PMS) in wastewater decontamination, yet their in-situ regeneration remains a significant challenge. This study successfully achieves in-situ real-time regeneration of Ov on CuO surfaces through simple alkali etching without interrupting the contaminant removal process. The surface hydroxyl groups introduced by alkali treatment significantly reduce the formation energy of Ov on CuO surfaces from 1.60 eV to 0.38 eV. Both experimental results and density functional theory calculations reveal that the high activity of CuO relies on the synergy of surface hydroxyl groups and Ov. This synergy increases the antibonding states below the Fermi level and the electron spin density of Cu near Ov, thereby promoting electron transfer from CuO to PMS. As a result, by just adding an equimolar amount of alkali relative to PMS in CuO/PMS system, the degradation rate constant of sulfamethoxazole (SMX) greatly increases by 42 times. The primary reactive oxygen species in this system are sulfate radicals and hydroxyl radicals. Furthermore, OH-/CuO/PMS system exhibits a long-term stability (> 300 h) for SMX removal in a real water matrix. This work provides a highly executable method to in-situ real-time regenerate Ov on CuO surfaces, representing significant progress in the critical yet underappreciated field of catalyst regeneration.

In this study, we examine the Metal–Insulator Transition (MIT) in two-dimensional p-Si/SiGe/Si systems at very low temperatures (0.3–1.6 K) under magnetic fields up to 18 T. The main objective is to determine the critical field Bc​ marking the transition between metallic and insulating regimes. Electrical conductivity was analyzed using six complementary methods, each based on a distinct theoretical model. This multi-approach analysis provides reliable and consistent results, revealing Bc≈7.2T. The findings contribute to a deeper understanding of quantum transport phenomena and offer perspectives for spintronic and quantum semiconductor device applications.

Abstract The Gibbs free energy of the magnetic superconductor FeTe 0.5 Se 0.5 has been analyzed in conjunction with the Werthamer–Helfand–Hohenberg (WHH) equation at a critical temperature (Tc) of 12 K. This study presents the temperature dependence of the upper critical magnetic field (Hc 2 ), coherence length (ξ GL ), penetration depth (λ GL ), and critical current density (Jc) of the FeTe 0.5 Se 0.5 superconductor. Using experimentally obtained values, phase diagrams were constructed, showing that Hc 2 , ξ GL , λ GL , and Jc exhibit non-linear temperature dependence and approach zero as T approaches Tc. The large values of the Ginzburg–Landau (GL) characteristic parameters indicate that FeTe 0.5 Se 0.5 is a strongly type-II superconductor. The results obtained in this work are in good agreement with previous experimental findings on FeTe 0.5 Se 0.5.

Abstract Polytypism in transition metal dichalcogenides (TMDs) introduces an additional degree of freedom for tailoring the electronic properties of layered van der Waals materials. Polytypes with larger unit cells, spanning four or six layers, can be viewed as natural homostructures, since their atomic composition remains identical across the layers. The resultant crystalline environments can potentially give rise to exotic electronic states, earning these materials recent attention. In this study, we examine structural and charge transport properties of metallic and superconducting 4H a -NbSe 2 . We find that the compound has a highly disordered stacking of layers, which impedes interlayer coherence, as demonstrated by detailed out-of-plane resistivity measurements, and effectively tunes the bulk system towards an atomically thin limit. The disordered structure largely accounts for the enhanced resistivity anisotropy and superconducting upper critical field, when compared to 2H a -NbSe 2 . This phenomenon can be exploited to promote quasi-two-dimensional physics in bulk crystals, and our study also underscores the importance of thorough structural characterization when investigating large-unit-cell polytypes of TMDs.

Higher critical currents yet faster vortex creep in EuBa2Cu3Oy films containing coherent artificial pinning centers