Browse Articles

Laser Interstitial Thermal Therapy for Brain Tumors: A Prospective Multicenter Analysis of Patients From the LAANTERN Study

PURPOSE Laser interstitial thermal therapy is a surgical tool used to ablate brain tumors, radiation necrosis, and epileptic foci. Data from the LAANTERN prospective multicenter registry (ClinicalTrials.gov identifier: NCT02392078 ), containing patients with tumor from 25 US centers between 2015 and 2023, were analyzed to determine clinical outcomes. METHODS All patients with primary or metastatic brain tumors treated with LITT using the Monteris NeuroBlate System were included in this analysis. Demographics, intraprocedural data, adverse events, survival data, and data pertaining to functional status over time were prospectively collected and then analyzed. Both univariable and multivariable analyses were performed. RESULTS A total of 787, primary (445) and metastatic brain tumor (342), patients were included. The median age was 59.6 years and the median pediatric age 15 years (n = 18). The median length of hospital stay was 32.4 hours, and 62.6% avoided intensive care unit admission. The adverse event rate was 12.8%, with 65.5% of events considered transient. Mortality rate was 0.25%. Anticonvulsants were stopped in 30%-40% of patients, and 80% of patients stopped steroids after LITT. Quality of life remained stable up to 3 years post-LITT. Greater extent of ablation (EOA) and smaller lesion size were associated with significant improvements in survival outcomes in patients with high-grade glioma and recurrent metastases. CONCLUSION The data from this largest, prospective LITT cohort support the consideration of LITT as a cytoreductive tool for patients with primary and metastatic tumor with short hospital stays, low complication rates, and preserved functional status. The EOA in glioblastoma and lesion volume in metastatic disease emerge as factors that may guide patient selection.

Immunotherapy and Targeted Therapy for Advanced Gastroesophageal Cancer: ASCO Living Guideline, Version 2026.1.2

This guideline has been updated. This ASCO Living Guideline is reviewed on an eight-week cycle. Please see the online dynamic version for the latest updates. Living guidelines are developed for selected topic areas with rapidly evolving evidence that drives frequent change in recommended clinical practice. Living guidelines are updated on a regular schedule by a standing expert panel that systematically reviews the health literature on a continuous basis, as described in the ASCO Guidelines Methodology Manual . ASCO Living Guidelines follow the ASCO Conflict of Interest Policy Implementation for Clinical Practice Guidelines . Living Guidelines and updates are not intended to substitute for independent professional judgment of the treating clinician and do not account for individual variation among patients. See appendix for disclaimers and other important information (Appendix I and Appendix II). Updates are published regularly and can be found on the ASCO Publications website .

Achieving low write error rates in perpendicular spin–orbit torque MRAM: A micromagnetic modeling feasibility study

We report a micromagnetic modeling study of switching perpendicularly magnetized free layers with spin–orbit torques (SOTs) generated by spin currents consisting of only orthogonal (conventional SOT) as well as both orthogonal and collinear (unconventional SOT) spin polarizations relative to the free layer (FL) magnetization. Focusing on the FL diameter of 50 nm, for conventional SOT, we find relatively high probabilities of FL back-hopping or incomplete switching at room temperature (T) for several bias configurations that deterministically switch the FL at T = 0 K, including in-plane bias field with and without Dzyaloshinskii–Moriya interaction (DMI) as well as the field-free case with DMI in the presence of field-like torque. For unconventional SOT, fast, field-free deterministic switching is found at T = 0 K for orthogonal y-spin SOT efficiency θy = 0.3 when collinear z-spin efficiency θz/θy > 0.25. Such large ratio is needed to change the nature of the magnetization switching from a non-uniform state with dominant component along y to an almost fully reversed and uniform state along -z, resulting in thermally robust and complete switching without back-hopping. In addition, the presence of z spins of such magnitude results in lowering of the switching current density by a factor of about 3, depending on the damping parameter α of the FL (more for lower α). Based on these results, we conclude that achieving low write error rate operation in perpendicular SOT MRAM is not feasible using approaches that exploit conventional SOT, but it should be straightforward to achieve with unconventional SOTs that meet parameter values determined by this study.

A method for enhancing the temperature measurement range of fiber specklegram sensors based on the integrated speckle intensity probability density function

Fiber specklegram sensors based on correlation demodulation suffer from rapid loss of correlation when the measured specklegram deviates too far from the reference image, causing their dynamic range to be limited by the saturation of the correlation coefficient. This restricts their application in wide-range temperature sensing. To overcome this limitation, we propose a novel demodulation method based on the integrated speckle light intensity probability density function, adopting the probability value of a specific light intensity interval as the characteristic parameter to enhance the dynamic range of fiber specklegram sensors. This paper elucidates the fundamental mechanism by which ambient temperature variations induce changes in the fiber length, diameter, and refractive index, subsequently leading to variations in the transmission modes and ultimately affecting the parameters of the integrated speckle light intensity probability density function. Theoretical derivation establishes the relationship between the probability value of a specific light intensity interval and the temperature change, thereby clarifying the principle of the proposed method for temperature sensing. A single-mode–no-core–multimode fiber structure is used as the sensing unit to perform principle verification and comparative experiments. The experimental results indicate that, within the operational temperature range of the experimental setup, our method expands the usable temperature range from 60–130 to 60–170 °C compared to the standard zero-mean-normalized cross correlation approach, achieving a 57.14% increase in the dynamic range. A slight reduction in linearity is observed and discussed, but the overall performance confirms that the proposed method substantially enhances the temperature measurement capability of fiber specklegram sensors.

Calculation of backscattering correction factors in AES for compounds: Unraveling matrix effects

Backscattering correction factor (BCF) data are essential for quantitative Auger electron spectroscopy (AES) analysis. This study computes BCFs for nine oxides and three zinc chalcogenides by using a Monte Carlo method that incorporates dielectric function theory for discrete inelastic events and Mott scattering cross section for elastic interactions. Results demonstrate that the BCF is highly sensitive to the mean atomic number of the matrix. Comparative analysis with NIST data reveals that the continuous slowing down approximation (CSDA) based model systematically underestimates the BCFs for heavy metal oxides, such as HfO2 and ZrO2. In these high-Z matrices, intense large-angle elastic scattering spatially distributes electron trajectories to be close to the surface region and thereby substantially increasing BCF. While our calculations align perfectly with NIST values for low-Z chalcogenides, the pronounced discrepancies in the heavy oxides definitively delineate the physical limits of the CSDA approach. Ultimately, this work provides a refined theoretical basis for eliminating systematic uncertainties in high-precision quantitative surface analysis by AES.

Thermodynamically admissible neural solvers for stiff electro-elastodynamics via exact geometric constraints

Physics-Informed Neural Networks (PINNs) serve as continuous, mesh-free solvers for partial differential equations, but they frequently encounter optimization failures when applied to strongly coupled, stiff multiphysics systems. In piezoelectricity, the disparity in energetic scales between mechanical stress and electric displacement creates severely ill-conditioned loss landscapes, resulting in gradient pathologies. Standard PINN formulations rely on penalty-based soft constraints for boundary and initial conditions, which exacerbate this stiffness, leak unphysical energy, and corrupt boundary stress calculations. In this work, we present a constrained PINN architecture for 1D coupled electro-elastodynamics that structurally bypasses this gradient competition. By applying the quasi-static approximation and utilizing analytical distance functions, we enforce exact Dirichlet boundaries and second-order time initial conditions directly within the neural network’s topology. This geometric constraint restricts the optimizer to a physically consistent energy manifold and enables recovery of maximal boundary stresses without internal gradient noise, a capability that is critical for predicting mechanical fatigue and failure in high-frequency transducer architectures. Stabilized by a deterministic quasi-Newton optimization stage, our fully constrained model resolves the mechanical displacement and electric potential fields with a global relative L2 error of O(10−5). These results demonstrate that the gradient pathologies typically observed in stiff multiphysics PINNs can be systematically neutralized through the exact algebraic imposition of boundary and initial constraints.

Thermoelastic dynamics of a nanoscale metallic film: Role of bilayer coupling revealed by extreme ultraviolet transient gratings

We investigate the thermoelastic dynamics of an 80 nm titanium thin film supported by a Si3N4 membrane by extreme-ultraviolet transient-grating (EUV-TG) spectroscopy across varying excitation fluences. A dominant oscillatory response at 143.8–150.6 GHz from time-domain fits is identified as a guided Lamb wave of the Ti/Si3N4 bilayer membrane with an in-plane phase velocity of approximately 6.3 km s−1. The near-coincidence of the Ti longitudinal and Si3N4 transverse acoustic velocities (∼6.1 km s−1) means that the dominant guided mode phase velocity simultaneously approximates both—a direct fingerprint of strong mechanical coupling between the layers. With increasing fluence, a systematic phase velocity increase of 4.7% is observed. A lower-frequency feature near 20–25 GHz is also detected, consistent with a breathing-type thickness response driven by transient uniform stress. Thermal relaxation analysis yields effective in-plane thermal diffusivities of (1.3–2.7) × 10−6 m2 s−1 and thermal conductivities of approximately 3–7 W m−1 K−1, significantly reduced relative to bulk Ti and consistent with boundary-limited heat transport in the confined membrane geometry. By combining nanometer-scale spatial selectivity with picosecond temporal resolution, EUV-TG enables simultaneous access to guided elastic wave propagation and nanoscale in-plane thermal transport in metallic membranes under non-equilibrium excitation. These results demonstrate how nanoscale confinement and multilayer coupling modify thermoelastic dynamics relative to bulk materials and highlight EUV-TG as a powerful tool for probing ultrafast thermoelastic dynamics in thin metallic films.

Quantifying the Correlation Between Capacity Utilization and Electrolyte Dosage for Ultrahigh‐Energy‐Density 769 Wh Kg ⁻¹ Rechargeable Lithium Metal Batteries

ABSTRACT The pursuit of high‐energy‐density lithium metal batteries requires simultaneous optimization of electrode architecture, electrolyte formulation, and interfacial stability. Here, we establish a fundamental parameter g(σ e , D e ) that quantifies the relationship between electrolyte dosage and capacity utilization in ultra‐thick electrodes (>100.0 µm), enabling precise determination of the minimal electrolyte requirement (1.1 g Ah −1 ). Through systematic investigation of electrolyte compatibility with high‐loading cathodes (> 10.0 mAh cm −2 ) at high voltages (4.8 V), we develop an optimized formulation that forms stable interfaces while suppressing parasitic reactions. By integrating these advances—including a lightweight lithium metal anode—we demonstrate a 54.2 Ah pouch cell achieving 769 Wh kg −1 , representing a 150% improvement over conventional lithium‐ion batteries. This work provides both theoretical and practical frameworks for engineering next‐generation batteries through electrolyte minimization and interface stabilization.

Cationic Complex Polymer Separator Confined Anionic [Zn(OH) ₄ ] ^2‒ Reduction for Stable Alkaline Batteries

ABSTRACT Unlike neutral aqueous batteries with cationic Zn 2+ as the charge carrier, alkaline batteries with anionic [Zn(OH) 4 ] 2‒ and OH ‒ are actually commercially feasible and thermodynamically stable thanks to their ability to suppress hydrogen evolution. Whereas commercial separators in alkaline batteries, without ion regulation capability, fail to suppress severe dendrite and passivation of anionic [Zn(OH) 4 ] 2‒ and accelerate ion transport of anionic OH ‒ . Herein, we tailor the coordination structures of alkali‐stable cationic complexes in polymer separators (CCPS) to construct anionic OH ‒ selective transfer channels. Synchrotron spectroscopic characterizations and theoretical calculations reveal that the low‐coordination cationic complexes expose more positive charge density, electrostatically attracting more negative charge from [Zn(OH) 4 ] 2‒ . In situ electrochemical digital holography technology and time‐of‐flight secondary ion mass spectrometry analyses further confirm the homogeneous [Zn(OH) 4 ] 2‒ distribution at the CCPS‐electrode interface, oriented Zn deposition, and impeded passivation. As a result, CCPS enables alkaline Zn||Cu cells to operate over 5500 cycles at 1 mA cm ‒2 with a high coulombic efficiency of 99.99%. Alkaline Ni–Zn batteries exhibit ultrastable cycling over 1000 cycles at 6 C and maintain 86.17% of their maximum capacity at 10 C. Our work may provide practical and effective separator strategies to accelerate the commercialization of alkaline batteries.

Low‐Dimensional Zero Thermal Expansion Enables Ultrastable Thermo‐Optics in YAl ₃ (BO ₃ ) ₄ Single Crystal

ABSTRACT Zero‐thermal‐expansion (ZTE) materials are critical for stabilizing device performance under thermal fluctuations. Traditionally, achieving enhanced thermal stability has required three‐dimensional (3D) ZTE, a stringent condition that severely limits material availability. Here, we show that low‐dimensional ZTE can be realized in single crystals by orienting ubiquitous bond rotations along specific crystallographic axes in the framework structures, thus relaxing the strict requirements for 3D ZTE. This approach enables a two‐dimensional ZTE response, as demonstrated in a trigonal YAl 3 (BO 3 ) 4 (YAB) crystal, which exhibits an ultralow thermal expansion coefficient of −0.02(7) MK −1 within the ab plane from 83 to 180 K. The practical impact of this low‐dimensional ZTE is evidenced by the thermo‐optical performance of YAB crystal: within the ZTE temperature range, the thermo‐optical coefficient varies by only 0.03(2) × 10 −8 K −2 in the ZTE plane, approximately two orders of magnitude lower than those of conventional optical materials. This study establishes a new design strategy for functional ZTE materials and highlights the application potential of dimensionally confined ZTE effects in precision optical and electronic devices.

Localized Tuning Fields for 3D Hand Position in the Primary Motor Cortex and Premotor Cortex of Macaques

A central question in motor neuroscience is how the brain represents the state of the limbs to guide volitional movements. While the primate motor cortex is known to encode movement kinematics, such as velocity and direction, whether it also maintains a direct and explicit representation of hand position in 3D space remains debated. To address this, we recorded the activity of single neurons in the primary motor cortex (M1) and dorsal premotor cortex (PMd) of two male rhesus macaques performing a naturalistic, self-paced 3D reach-and-grasp task. We found significant populations of neurons in both M1 (36.2%) and PMd (21.3%) that are robustly tuned to the instantaneous 3D position of the hand. In these neurons, the tuning for hand position—characterized by localized, elongated fields—coexists with tunings for other kinematic variables, reflecting the principle of mixed selectivity. Critically, the spatial organization of these representations differs between the two areas: M1 fields are systematically oriented along cardinal axes and exhibit multi-scale spatial clustering, whereas PMd fields are more randomly organized. Furthermore, a small subset of these hand position-tuned cells is sufficient to decode the hand’s 3D trajectory with high fidelity. Our findings demonstrate that an explicit and functionally organized representation of 3D hand position is a fundamental component of primate motor cortex, complementing dynamic motor signals to support high-fidelity motor control. Significance Statement To guide skilled actions, the brain must track the hand's location. While the motor cortex is known for controlling movement commands, we reveal it also creates an explicit, highly organized 3D map of hand position. This neural representation is systematically structured, differing between primary and premotor areas. This discovery reshapes our understanding of motor control, showing the brain merges spatial information (“where”) with motor commands (“how”) of the hand in the same areas. These insights are crucial for creating more effective brain-computer interfaces for individuals with paralysis.

Anterior cingulate cortex projections to the amygdala in primates: topographic and layer-specific organization underlying emotion and mood regulation

Emotion and mood regulation critically depends on interactions between the anterior cingulate cortex (ACC) and the amygdala. However, the detailed architecture of ACC projections to their major targets, the basal (BA) and accessory (AcBA) basal nuclei of the amygdala, remains unclear. To address this issue, a combined retrograde and anterograde tracing with viral vectors were performed in macaques of either sex to map the projection patterns from the pregenual (pgACC), subgenual (sgACC), and dorsal (dACC) subareas. Data revealed that ACC neurons projecting to the BA arose predominantly from the superficial layers (II/III) of all subareas and the deep layers (V/VI) of the sgACC, whereas ACC neurons projecting to the AcBA originated mainly in the deep layers of the sgACC and dACC. The present study defines the topographic and layer-specific organization of ACC–amygdala connectivity in primates and subserves to provide an anatomical basis for future causal and translational approaches, such as targeted interventions against ACC-related mood disorders. Significance Statement Emotion and mood regulation critically depends on interactions between the anterior cingulate cortex (ACC) and the amygdala, and their dysfunctions have been implicated in mood disorders such as depression. However, the detailed organization of primate ACC–amygdala circuitry remains to be fully understood. Notably, the existence of projections from the pregenual ACC (pgACC) to the basal nucleus of the amygdala (BA) has been controversial. Using viral vector-based neural tracings in macaques, we have identified a distinct pgACC–BA pathway and shown that this pathway arises predominantly from the superficial layers of the cortex. Such unexpected laminar origin, atypical for cortico–subcortical projections, reveals a previously unrecognized circuit architecture and challenges prevailing models of cortico–amygdala linkage involved in mood disorders.

High current ultrawide bandgap AlGaN pin diodes with low on-resistance and UVC emission

We report ultrawide-bandgap AlGaN pin diodes with high forward current density and deep-ultraviolet (DUV) electroluminescence signaling efficient carrier injection. The devices incorporate a 100 nm unintentionally doped intrinsic layer between polarization-doped n- and p-type regions, grown by plasma-assisted molecular beam epitaxy on bulk AlN substrates. Electrical characterization reveals current densities up to ∼28 kA/cm2, differential on-resistances below 1 mΩ cm2, ideality factors approaching 1.7, and a cutoff frequency fco = (2πRonCoff)−1 = 30.8 GHz. Capacitance–voltage measurements confirm a reduced junction capacitance relative to a pn diode without the i-layer, while electroluminescence shows ultraviolet emission at 248 nm from the polarization-doped regions. These results establish AlGaN pin diodes as a promising platform for high-speed, high-voltage, and DUV optoelectronic devices, offering a scalable approach to next-generation ultrawide-bandgap electronics and photonics.

Erratum: Safety, Tolerability, and Antitumor Activity of Zipalertinib Among Patients With Non–Small-Cell Lung Cancer Harboring Epidermal Growth Factor Receptor Exon 20 Insertions

Molecular dynamics study of ferroelectric switching mechanisms in monodomain and 180° domain walls of BaTiO3 and PbTiO3

Understanding the intrinsic switching mechanisms is essential for controlling polarization domains and enabling their integration into next-generation nanoelectronic devices. In this study, we employ molecular dynamics (MD) simulations to investigate the electric field induced polarization switching behaviors of two representative ferroelectric materials, BaTiO3 and PbTiO3 single crystals, initialized with either monodomain configurations or 180° domain walls. By investigating both macroscopic switching dynamics and microscopic dipolar patterns, we identify distinct switching pathways governed by the initial domain structure and material-specific characteristics. Our results reveal that BaTiO3 exhibits a transition from Kolmogorov–Avrami–Ishibashi (KAI)-type switching to nucleation-limited switching (NLS) at intermediate fields when initialized with domain walls, from the NLS switching to homogeneous switching (HS) at high fields, regardless of the initial configuration. In contrast, PbTiO3 single crystals show a strong dependence on the initial domain state: Systems with pre-existing domain walls follow a KAI-to-HS transition, while monodomain systems follow an NLS-to-HS pathway. These differences are attributed to variations in activation fields associated with nucleation vs domain wall motion. Beyond macroscopic kinetics, our simulations demonstrate complex microscopic features. PbTiO3 exhibits polarization vortices and curved dipolar structures during switching, indicative of non-Ising type behavior. In comparison, BaTiO3 displays anisotropic domain growth and directionally biased anisotropic chain correlations. These results provide a comprehensive view of intrinsic switching mechanisms and offer insight into the design of ferroelectric materials with tailored switching characteristics for advanced nanoelectronic devices.

Mosunetuzumab With Response-Adapted Polatuzumab Vedotin and Obinutuzumab in Untreated Indolent B-Cell Non-Hodgkin Lymphoma

PURPOSE Chemoimmunotherapy has been the standard approach for untreated indolent B-cell lymphoma. We hypothesized that initial use of the CD3/CD20 bispecific mosunetuzumab followed by response-adapted polatuzumab vedotin and obinutuzumab would yield an optimized chemotherapy-free approach. METHODS Previously untreated patients with follicular lymphoma (FL) and marginal zone lymphoma (MZL) with indication for treatment received eight cycles of mosunetuzumab. Those not achieving a complete response (CR) by positron emission tomography-computed tomography (PET-CT) following mosunetuzumab could go on to receive six cycles of polatuzumab vedotin and obinutuzumab. The primary end point was best overall response rate (ORR) of CR by fluorodeoxyglucose-PET-CT. RESULTS The 42 enrolled patients had a median age of 60 years (range, 36-83), 39 were stage III to IV (93%), 37 (88%) had FL, and 13 (31%) had bulk >7 cm. The end-of-treatment ORR and CR rates were 100% and 86%, respectively. The ORR and CR to mosunetuzumab alone were 100% and 71%, respectively. With a median follow-up of 34 months, the 2-year progression-free survival (PFS) was 89% (95% CI, 80 to 100) and the 2-year overall survival was 100%. The four progression events included CD20 loss (2) and histologic transformation (2). Cytokine release syndrome occurred in 27 patients (64%), but all were grade 1. No patients required tocilizumab. CONCLUSION Single-agent mosunetuzumab as well as response-adapted polatuzumab vedotin and obinutuzumab yield encouraging CR rates and PFS with limited toxicity among previously untreated patients with FL and MZL. This chemotherapy-free strategy may provide a template for larger study designs for personalized approaches in this population that balances efficacy with safety.

Physics-driven mechanisms governing the pharmacokinetics and immune fate of gold nanoparticles. I. An ADIE framework perspective

Gold nanoparticles’ (GNPs) clinical translation requires a mechanistic understanding of their pharmacokinetics at the nano–bio interface. Classical ADME (Absorption, Distribution, Metabolism, Elimination) models describe biodegradable materials but do not capture the behavior of inorganic nanomaterials. The in vivo fate of GNPs is governed not by metabolic biochemistry but by transport physics, interfacial energetics (thermodynamics), and corona-encoded biological recognition. This Perspective introduces the ADIE (Absorption, Distribution, Interaction, Elimination) framework, in which Interaction becomes the central determinant of nanoparticle fate. Distribution reflects convection and diffusion transport, while Brownian motion and thermodynamics drive protein corona (PC) formation. The composition of the corona determines which liver cell populations engage each particle, directing GNPs toward Kupffer cells, liver sinusoidal endothelial cells, or hepatocytes through receptor-based pathways. Interaction is defined as the combined processes of biotagging (adsorption of PC that assigns each particle a biological identity) and biorecognition (receptor-mediated engagement of that identity by immune and non-immune liver cells). Within ADIE, Interaction replaces Metabolism because GNPs undergo biotagging rather than biochemical transformation. Elimination depends on size and uptake route. Ultrasmall GNPs below 6 nm undergo renal filtration, whereas larger or non-stealth particles enter hepatic processing. Kupffer cell uptake results in immune sequestration; LSEC uptake leads to endothelial retention; hepatocyte uptake enables limited biliary elimination in which a small fraction of intact GNPs is transported to the canalicular membrane for fecal excretion. Thus, the liver functions primarily as a retention organ but also provides a minor excretory pathway. This physics-driven Perspective (Paper I) establishes the mechanistic foundations of ADIE and explains how nano–bio interactions govern GNP fate. The companion article (Paper II) extends these principles to broader pharmacokinetic implications for nanoparticle biodistribution, retention, clearance, and design.

Mechanisms of dislocation loops influencing damage evolution of single crystal copper under uniaxial and triaxial tension

Dislocation loops are typical irradiation defects that significantly influence the mechanical behavior of irradiated materials. In this work, molecular dynamics simulations are performed to investigate the influence mechanisms of dislocation loops on damage evolution of single crystal copper, with a focus on the effects of loading conditions (uniaxial and triaxial strain tension) and dislocation loop types (interstitial and vacancy loop). Under uniaxial strain tension, interstitial and vacancy loops exhibit distinct effects on initial plasticity but comparable effects on damage evolution. Vacancy loops induce plasticity earlier than interstitial loops, while interstitial loops exhibit faster plastic development once plasticity is activated, leading to comparable damage evolution at later stages. Under triaxial strain tension, voids nucleate directly at the sites of both dislocation loops. Vacancy loops induce void nucleation earlier than interstitial loops due to their pre-existing dislocation junctions, whereas the latter require dissociation to form such junctions before void nucleation. Additionally, the sensitivity of damage evolution to loop size depends on both loading conditions and loop types. These findings provide valuable insights into the irradiation defect-mediated damage behavior and offer mechanistic support for constructing theoretical models of irradiated materials under extreme conditions.

Rapid general electromagnetic analysis of metallic surfaces via conformal energy minimization

We recently found that the electromagnetic scattering problem can be solved efficiently using an approach that expresses the fields in terms of a set of orthonormal basis functions. In this paper, we apply computational conformal geometry with the conformal energy minimization (CEM) algorithm to make possible fast solution of finite-frequency electromagnetic problems involving arbitrarily shaped, simply connected planar metallic surfaces. The CEM algorithm enables the transformation of arbitrary simply connected surfaces into a disk, where orthogonal basis functions can be defined and electromagnetic analysis can be significantly simplified. We demonstrate the effectiveness and efficiency of our method by investigating the resonance characteristics of two planar metallic surfaces: a square plate and a four-petal plate with semicircular side features. Our method extracts the circuit parameters, resonance frequencies, and resonance field distributions within seconds, accelerating resonant frequency determination by three orders of magnitude over conventional finite-element methods (e.g., COMSOL). Moreover, it directly and efficiently reveals low-energy, doubly degenerate resonance modes. These findings provide an analytical approach for calculating electromagnetic fields on complex geometries, contributing to the development of high-performance electromagnetic devices.

Electrical properties of electrochemically energized n-GaN under reverse-bias conditions

Electrochemical energization of n-GaN was conducted under reverse-bias conditions as well as forward-bias conditions that were used in our previous studies for anodization, and electrical properties of energized n-GaN were examined. The surface composition and electrical properties of the energized n-GaN were evaluated by x-ray photoelectron spectroscopy (XPS) and temperature-dependent Hall-effect measurements, respectively. XPS analysis revealed that surface oxidation occurred even under reverse-bias conditions. Furthermore, while the electron concentration slightly increased under forward-bias conditions, it decreased by four to five orders of magnitude under reverse-bias conditions, suggesting significant electron trapping. These results clearly indicate that the effects of electrochemical energization on n-GaN differ significantly between forward- and reverse-bias conditions. Based on these findings, a surface conceptual illustration of n-GaN that explains these results is proposed.