Browse Articles

Single-photon detector based on absorption in waveguide quantum electrodynamics

Single-photon detection plays important roles in implementing desired quantum information processing. In this work, we propose a single itinerant photon detector based on absorption by two interacting atoms coupling to a waveguide, which can work in the microwave regime. Both the cases of giant and small atoms are considered. Each atom is modeled as a three-level system, with only one transition coupling to the waveguide. Our analysis reveals that, for a single atom coupled to the waveguide, the maximum detection probability is intrinsically limited to 0.5. This limit, however, can be lifted under perfectly chiral coupling, where unit detection probability becomes achievable. For the non-chiral case, we show that when a giant molecule consisting of two giant atoms with direct interaction couples to the waveguide, the single-photon detection probability can reach the ideal value of 1. Furthermore, we extend the model to the regime of small atoms and show that perfect single-photon detection remains attainable by appropriately tuning the direct coupling strength and the interatomic separation. These results provide a feasible route toward high-efficiency microwave single-photon detection based on engineered atom-waveguide interactions.

Optimization of proton-exchange membrane fuel cell via multi-objective CFD-based design

Experimental evidence of strong intrinsic defect-induced phonon scattering in 2D non-layered β-In2S3

β-In2S3, as a typical two-dimensional (2D) non-layered material, has recently attracted growing attention for exploring novel physical properties beyond van der Waals layered materials. Here, we measured the cross-plane thermal conductivity of β-In2S3 thin films in the temperature range of 78–355 K and at various thicknesses using frequency-domain thermoreflectance. Remarkably, the thermal conductivity remains at around 1 W m−1 K−1 under all measured conditions, demonstrating no significant dependence on either temperature or thickness. This anomalously weak dependence originates from the abundant intrinsic indium vacancies in β-In2S3, which occupy one-third of the tetrahedral sites. These vacancies significantly shorten the phonon mean free path and enhance phonon scattering, resulting in a low and nearly constant thermal conductivity. This study fills the research gap regarding the thermal transport properties of β-In2S3 and provides new insights into the impact of intrinsic point defects on heat conduction in 2D non-layered materials.

Effect of thymus vulgaris essential oil as an antifungal agent on the flexural strength, surface roughness, and color stability of polymethyl methacrylate acrylic resin

Outside Back Cover: Atomically Precise Interfacial Engineering on Tin‐Silicon Oxo Clusters for Sub‐8 nm Lithography (Angew. Chem. Int. Ed. 16/2026)

Haptic light-emitting diodes: Miniature, luminous tactile actuators

We present haptic light-emitting diodes (HLEDs), luminous thermopneumatic actuators that directly convert pulsed light into mechanical forces and displacements. Each device packages a miniature surface-mount light-emitting diode in a gas-filled cavity that contains a low-inertia graphite photoabsorber. The cavity is sealed by an elastic membrane, which functions as a working diaphragm. Brief optical pulses heat the photoabsorber, which heats the gas. The resulting rapid pressure increases generate forces and displacements at the working diaphragm. Millimeter-scale HLEDs produce forces exceeding 0.4 N and displacements of 0.9 mm at low voltages, with 5–100 ms response times, making them attractive as actuators providing tactile feedback in human–machine interfaces. Unusually, these actuators are also light-emitting, as a fraction of optical energy is transmitted through the membrane. These photomechanical actuators have many potential applications in tactile displays, human interface engineering, wearable computing, and other areas.

Essential oil and extract of clevenger’s waste of hymenocrater calycinus (boiss.) benth. as a non-toxicity option for cutaneous burns according to traditional use

Aggregation‐Driven Thorough Cascaded Proton Transfer Process Targeting Ultralow‐Threshold Near‐Infrared Organic Single‐Crystal Lasers

ABSTRACT Near‐infrared (NIR) organic solid‐state lasers (OSSLs) are technologically crucial in lasing communication systems, yet they still suffer from the high threshold and low optical gain due to the limited exciton utilization rate. Excited‐state double proton transfer (ESDPT) processes of organic gain materials offer promising gain mechanisms for NIR OSSLs due to the favored six‐electronic‐level energy systems and large red‐shifted stimulated emission. Herein, we proposed a novel strategy aimed at modulating the ESDPT process through aggregation effect, where crystallization‐enhanced thorough cascaded ESDPT process facilitates the exciton utilization rate and thus enables an ultralow lasing threshold. Impressively, the strong J ‐type coupling of 4260 cm −1 in DDMC single‐crystal microwires effectively stabilizes TB* level by lowering excited state energy, supporting a thorough ESDPT process. Consequently, all excited electrons decaying by radiative transitions participate in stimulated emission, enabling a high‐gain six‐level energy system with efficient population inversion density (∆ N ). Activated by this efficient energy‐level system, the NIR single‐crystal lasing at ∼870 nm was successfully realized with a record‐low threshold of 486 nJ cm −2 . Our work elucidates the fundamental mechanism underlying aggregation effects on ESDPT gain materials, offering effective strategy to enhance the exciton utilization rate for low‐threshold and high‐gain NIR OSSLs, and even the electrically‐pumped NIR OSSLs in the future.

A molecular selenium iodide cathode and hybrid electrolyte for solid-state Na–Se2I2 batteries

Challenges such as polyselenide shuttling and poor reaction kinetics persist in sodium–selenium (Na–Se) batteries. While solid-state Na–Se batteries could potentially eliminate the shuttle effect, they have received limited attention due to poor solid–solid interfacial contact and intrinsically sluggish conversion kinetics. Herein, we report a solid-state Na–Se2I2 battery that employs a low-melting point Se2I2 molecular cathode and a tailored hybrid solid electrolyte. At an operating temperature above its melting point, liquid Se2I2 establishes favorable liquid–liquid interfaces and enables a facile liquid–solid conversion pathway. Furthermore, the sodium super ion conductor (NASICON)/poly(ethylene oxide) hybrid electrolyte simultaneously dissolves polyselenides to promote redox kinetics and physically blocks their shuttling to ensure cycling stability. As a result, a reversible six-electron conversion reaction is achieved, and the solid-state Na–Se2I2 battery delivers a high specific capacity of 336 mAh g−1 at 0.1 C and a stable cycling over 200 cycles with 88.2% capacity retention at 0.5 C. The electrochemically active Se2I2 molecular design opens an alternative chemistry for selenium-based electrodes and provides a promising direction for future solid-state battery research.

Biomechanics of the tooth cervical region investigated using 3D digital image correlation, micro CT, and finite element analysis

Ultrahigh charge-to-spin conversion and tunneling magnetoresistance in quasi-two-dimensional <i>d</i> -wave altermagnet

The emergence of altermagnets has driven groundbreaking advances in spintronics. Notably, d-wave altermagnets support non-relativistic spin transport, efficient charge-to-spin conversion, and T-odd spin currents. In addition, their integration as electrodes in antiferromagnetic tunnel junctions (AFMTJs) enables a tunneling magnetoresistance (TMR) effect, allowing electrical detection of Néel vectors for next-generation memory devices. In this work, we investigate the non-relativistic spin transport properties of the quasi-two-dimensional (quasi-2D) d-wave altermagnet KV2Se2O and the TMR effect in KV2Se2O-based AFMTJs via first-principles calculations. Our results reveal that KV2Se2O exhibits both non-relativistic longitudinal spin polarization and a spin Hall angle exceeding 60% at room temperature, while KV2Se2O-based AFMTJs achieve a giant TMR ratio of 8.20 × 1013%, which remains robust against Fermi-level shifts. These findings highlight the anisotropic spin polarization inherent to d-wave staggered magnetism and underscore the critical role of Fermi surface topology in enhancing T-odd spin transport and the TMR effect in AFMTJs.

Climate variability shapes volatile composition and sensory quality in Coffea arabica cultivars

Inside Back Cover: Accelerating Catalyst Materials Discovery With Large Artificial Intelligence Models (Angew. Chem. Int. Ed. 16/2026)

Effective modulation of emission dynamics in Er:CaF2 crystal via oxygen anion engineering

In Er3+-doped CaF2 crystals, strong upconversion processes promote higher-lying emissions while limiting the population of the 4I13/2 level, undermining its 1.5 μm laser potential. In this work, we demonstrate that anion engineering through oxygen incorporation into Er:CaF2 allows manipulation of the erbium emission dynamics, significantly suppressing upconversion losses. Specifically, O2− is introduced as a charge-compensator in place of interstitial Fi− and shown to be favorably paired with Er3+ by first-principles calculations, which yields adjacent vacancy defects that serve as energy sinks for mid-infrared transitions. This structural modification provides an inhibitor for interrupting upconversion pathways and redirecting population to the 4I13/2 level. Moreover, robust 1.5 μm emission is preserved due to the suppressed formation of erbium clusters. These findings highlight the role of anion dopants in the modulation of structure–property relationships, thereby enabling effective tuning of the emission properties of optical materials.

Loop anchor tension band wiring for olecranon fractures reduces Kirschner wire migration rate: a retrospective comparative study

Control of ultrafast excitonic shift current-induced THz emission efficiency of layered single-crystalline MoS2

Following ultrafast photoexcitation, a semiconductor exhibits competing dynamics among photocarriers, many-body transient states of highly energetic excitons, and electron–hole liquid (EHL). Here, we show that femtosecond optical pulse excitation induces a transient excitonic shift current contributing to stronger terahertz (THz) emission from a single-crystalline bulk MoS2 at low temperatures. The control of dominating excitonic shift current is elucidated from excitation density-dependent experiments at varying temperatures. A strong decrease in the excitonic contribution beyond a critical fluence of 150 μJ/cm2 is observed at a very low temperature of 20 K. This behavior suggests the formation of a new quantum condensate, i.e., the EHL, in the regime when the exciton density is overwhelmingly large that the average spacing between exciton pairs is comparable to the exciton radius. Furthermore, the exciton density-dependent THz emission at varying temperatures is consistent with the Varshni model and the crystal Debye temperature of 260 K.

Optimization of asymmetric gyrostatic satellite kinematics in a resistive medium: A novel elliptic function solution

Abstract In this study, a new approach for solving the dynamic motion of an asymmetric satellite with optimally controlled torques is investigated. The satellite moves in an atmospheric resistance medium and is impacted by gyrostatic torque (GT). The Euler equations were used to formulate the governing satellite equations. A small parameter is introduced through the assumption of a small control torque magnitude. Using elliptic function theory, explicit expressions for the angular velocities in the unperturbed regime are derived, extending the classical Euler-Poinsot solutions to include coupled gyrostatic and control effects. The semi-optimal control law is derived from a minimum-energy objective functional and is shown to preserve the integrability structure of the system. Perturbation analysis yields evolution equations for the angular momentum and kinetic energy in the presence of resistive torques. Numerical validation outcomes with &lt; 10 -6 relative error over 100 rotation periods. Parametric studies reveal distinct operational regimes: gyrostatic amplification enhances momentum capacity while maintaining stability; medium resistance provides stabilization but increases compensatory energy consumption; and control axes exhibit specialized roles, with b 2 serving as the primary momentum driver and b 3 exhibiting inverse energy relationships. The analytical framework provides a 100x computational speedup for mission design optimization compared to direct numerical integration, with applications to the attitude control of asymmetric satellites in low Earth orbit. The findings directly apply to low-Earth-orbit satellites experiencing atmospheric drag, where optimal power management is crucial for mission longevity. Earth observation satellites, communication satellites, and space telescopes with complex, nonsymmetric geometries can benefit from the developed control torque optimization strategies, especially the discovery that different control axes serve specialized roles in energy management and attitude stability. The study’s insights into GT effects are particularly valuable for spacecraft with large spinning components, such as solar arrays or antennas, whereas elliptic modulus analysis provides essential guidance for mission planning and attitude determination algorithms.

Inside Front Cover: Low‐Temperature Reverse Water–Gas Shift Enabled by Magnetically Induced Catalysis (Angew. Chem. Int. Ed. 16/2026)

High-fidelity ghost imaging using untrained physics-driven dual-network framework at ultra-low sampling rates

Ghost imaging (GI) is a typical computational imaging technique that reconstructs two-dimensional and three-dimensional images from one-dimensional bucket detector signals under structured light illumination. By utilizing single-pixel detection, this technology is particularly advantageous in low-light environments and in spectral regions (e.g., infrared, ultraviolet, or x-ray), where high-performance array detectors are often impractical or prohibitively expensive. However, traditional GI methods suffer from poor image reconstruction quality at low sampling rates and high hardware requirements; additionally, the generalization issues of data-driven deep learning methods limit their practical applications. Here, we propose a physics-driven Dual Untrained Ghost Imaging Neural Network (DUGIN). By integrating a “coarse-to-fine” dual-network architecture with the physical model, our method utilizes the deep image prior to achieve stable optimization and effectively escape local optima. Furthermore, a general affine scale correction module is designed to compensate for the intensity scale bias caused by normalization, further improving reconstruction fidelity. Simulation and experimental results demonstrate that DUGIN achieves high-fidelity natural image reconstruction at a 5% sampling rate, showing significantly reduced image noise and clearer details compared to traditional differential ghost imaging and recent physics-driven Ghost Imaging using Deep Neural Network Constraint methods. This study provides a novel framework for GI technology and paves the way for its practical application.

Bacteriological quality and associated factors of locally prepared fresh fruit juices in Northeast Ethiopia