Superconductivity最新文献

{"title":"Enhanced-performance superconducting nanowire avalanche photodetector with staggered bends","authors":"Xu Zhao ,&nbsp;Ling-Dong Kong ,&nbsp;Jia-Ming Xiong ,&nbsp;Xiao-Yu Liu ,&nbsp;Hao Li ,&nbsp;Zhen Wang ,&nbsp;Li-Xing You","doi":"10.1016/j.supcon.2025.100186","DOIUrl":"10.1016/j.supcon.2025.100186","url":null,"abstract":"<div><div>Emerging quantum technologies and weak-light applications demand photon detectors with a simultaneously high counting rate and near-unity efficiency. Superconducting nanowire single-photon detectors can achieve &gt;90% system detection efficiency, but maintaining this efficiency at high counting rates remains challenging. Although parallel-configured superconducting nanowire avalanche photodetectors (SNAPs) reduce the recovery time, their designs intensify the current crowding effects at bends, leading to persistent challenges in achieving high system detection efficiency. We developed an optimized bend structure for meandered parallel nanowires called staggered bends, which increased the switching current by 11.3% in the 2-SNAPs. At 1064 nm, the optimized 2-SNAP and 3-SNAP with staggered bends achieved system detection efficiencies of 96.6% and 98.1%, respectively. Meanwhile, these devices maintain 90% system detection efficiency while achieving counting rates of 3.1 MHz and 10.3 MHz. This study establishes a practical framework for SNAPs with demonstrated performance metrics that could enable advancements in the frontiers of quantum information.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100186"},"PeriodicalIF":6.2,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of rare earth (RE) mixing in REBa2Cu3O7−x thin films, including RE2O3 nanoparticle formation, on in-field critical current density at 20K","authors":"M.H. Lai ,&nbsp;I. Kim ,&nbsp;J.P. Feighan ,&nbsp;T. Bedford ,&nbsp;J. Shen ,&nbsp;M.T. Moceri ,&nbsp;J. Huang ,&nbsp;X.T. Nguyen ,&nbsp;G. Di Martino ,&nbsp;H. Wang ,&nbsp;S.H. Moon ,&nbsp;A. Kursumovic ,&nbsp;J.L. MacManus-Driscoll","doi":"10.1016/j.supcon.2025.100171","DOIUrl":"10.1016/j.supcon.2025.100171","url":null,"abstract":"<div><div>The factors that influence high-field, low-temperature current carrying performance of coated conductors are complex. Using epitaxial thin films grown by pulsed laser deposition (PLD) made from (<span><math><msub><mrow><mi>Y</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>8</mn></mrow></msub></math></span>RE’<span><math><msub><mrow></mrow><mrow><mn>0</mn><mo>.</mo><mn>2</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>RE”<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>)Ba₂Cu₃\u0000 O<span><math><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>y</mi></mrow></msub></math></span> (YREBCO), where RE = rare earth targets, with and without liquid (L) additions, this work decouples the different complex effects (both positive and negative) of RE mixing. In doing so, we understand the outcomes of the separate effects of this mixing, and the incidental formation of (Y,RE’,RE”)₂O₃ nanoparticles. The YREBCO composition is chosen because it permits growth conditions to be the same and near-optimum for all the targets, <em>i.e.</em>, at the optimum temperature as for the growth of pure YBCO, the reference composition, to enable effective comparison of compositions. We find that a high RE ion size variance increases the RE₂O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> fraction but that <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> (20 K, 8 T) is decreased, owing to the associated atomic disorder. On the other hand, we find that for moderate variance (and moderate RE₂O₃ nanoparticle formation), <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> (20 K, 8 T) is increased. A liquid phase needs to be included to ensure minimal microstructural disorder of the YREBCO lattice caused by the RE₂O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> nanoparticle inclusions. Of the wide range of PLD target compositions explored, (<span><math><msub><mrow><mi>Y</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>8</mn></mrow></msub></math></span>Gd<span><math><msub><mrow></mrow><mrow><mn>0</mn><mo>.</mo><mn>1</mn></mrow></msub></math></span>Yb<span><math><msub><mrow></mrow><mrow><mn>0</mn><mo>.</mo><mn>1</mn></mrow></msub></math></span>)Ba₂Cu₃O<span><math><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>y</mi></mrow></msub></math></span> is determined to have the optimum moderate ion size variance. An approximate doubling of <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> (20 K, 8 T) compared to pure YBCO films results. Thus, the (<span><math><msub><mrow><mi>Y</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>8</mn></mrow></msub></math></span>Gd<span><math><msub><mrow></mrow><mrow><mn>0</mn><mo>.</mo><mn>1</mn></mrow></msub></math></span>Yb<span><math><msub><mrow></mrow><mrow><mn>0</mn><mo>.</mo","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100171"},"PeriodicalIF":5.6,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High critical current double-sided, thick-film REBa2Cu3O7−δ tapes by Advanced MOCVD","authors":"B. Sarangi ,&nbsp;J. Sai Sandra ,&nbsp;C. Reddy Aramadaka ,&nbsp;G. Majkic ,&nbsp;J. Jaroszynski ,&nbsp;V. Selvamanickam","doi":"10.1016/j.supcon.2025.100184","DOIUrl":"10.1016/j.supcon.2025.100184","url":null,"abstract":"<div><div>Enhancing the cost-effectiveness and performance of Rare Earth Barium Copper Oxide (REBCO) coated conductors remains a key objective for advancing applications in power transmission, fusion energy, particle accelerators, and rotating machines. One direct method to achieve this is by increasing the conductor’s critical current under operational conditions. This study introduces a major breakthrough in fabricating Zr-doped (Gd,Y) BaCuO double-sided tapes utilizing an Advanced Metal Organic Chemical Vapor Deposition (A-MOCVD) technique. A single-pass deposition resulted in uniform films of <span><math><mrow><mo>∼</mo><mn>4</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> on both sides of the tape, with critical current values at 20K and 20T consistently above 950 A/4 mm, peaking at 1100 A/4 mm. Additionally, a self-field transport critical current of 930 A/4 mm was attained in self-field conditions at 77 K, 0 T, translating to a critical current density of 2.9 MA/cm ². These results represent some of the highest reported performance metrics for REBCO tapes of this thickness, underscoring the potential of double-sided A-MOCVD processing for next-generation superconducting applications.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100184"},"PeriodicalIF":5.6,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropy modulation and band structure reconstruction induced by high pressure in Kagome metal GdV6Sn6","authors":"Rui Zhang ,&nbsp;Kaiyun Chen ,&nbsp;Shengnan Zhang ,&nbsp;Jianfeng Li ,&nbsp;Songrui Wei ,&nbsp;Xiaofan Yang","doi":"10.1016/j.supcon.2025.100174","DOIUrl":"10.1016/j.supcon.2025.100174","url":null,"abstract":"<div><div>The geometric frustrations and unique electronic structures in Kagome lattices normally give rise to various quantum matter ground states. V-based Kagome compounds, such as <em>A</em>V₃Sb₅, exhibit a complex phase diagram under hydrostatic pressure modulation. Herein, we report an electronic structure evolution in another novel V-Kagome system <em>R</em>V₆Sn₆, with pressures changing from 0 to 107 GPa, through density functional calculations. Our results reveal that the electronic density of GdV₆Sn₆ exhibits pronounced anisotropy under high pressures. Specifically, electronic structure instabilities stem from van Hove singularities are observed in the V-Kagome plane, while that remains robust up to approximately 40 GPa in the <em>M</em> momentum space. In the high-pressure regime (<span><math><mo>∼</mo></math></span>107 GPa), the newly formed saddle point approaches and crosses the Fermi level, enhancing the density of states (DOS) at the Fermi level. This potentially results in pressure-induced superconductivity, accompanied by the formation of charge channels. Our findings provide essential insights into the electronic structure of GdV₆Sn₆ under high pressures, offering a valuable model for investigating V-Kagome physics in <em>R</em>V₆Sn₆ compounds.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100174"},"PeriodicalIF":5.6,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rutherford MgB2 cable with 20 μm twisted filaments inside the Nb/CuNi/CuZn sheath","authors":"P. Kováč ,&nbsp;J. Kováč ,&nbsp;D. Berek ,&nbsp;M. Rindfleisch ,&nbsp;M. Búran ,&nbsp;T. Melišek ,&nbsp;I. Hušek ,&nbsp;M. Tomsic","doi":"10.1016/j.supcon.2025.100172","DOIUrl":"10.1016/j.supcon.2025.100172","url":null,"abstract":"<div><div>A fine-filamentary CuZn sheathed MgB ₂ wires produced by Hyper Tech Inc were used for 12 strand Rutherford cable of thickness 0.70–0.76 mm. Critical currents of short cable samples were measured at 4.2 K and external fields 4.0–8.0 T and also at temperatures 15–25 K and magnetic fields 1.0– 5.5 T. The threshold of engineering current density <span><math><mrow><msub><mrow><mi>J</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> Acm ⁻² for the cable size of 0.72 mm <span><math><mo>×</mo></math></span> 2.55 mm was obtained at field of 4.5 T and temperature 4.2 K and at 2.3 T for 20 K, respectively. Magnetization measurements of the cable with transposed strands and twisted <span><math><mrow><mn>20</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> filaments have shown reduced AC losses, but, the coupling currents loss contribution was still visible. AC losses measured for the same size Rutherford cable made of single-core wires demonstrate the effect of well decoupled filaments. Consequently, the cabling of thin single-core MgB ₂ wires shows a promising way for low loss conductors suitable for AC applications.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100172"},"PeriodicalIF":5.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced intelligent quench diagnostics for high temperature superconducting coils based on principal component analysis of voltage harmonic ratios and Support Vector Machine","authors":"Yahao Wu,&nbsp;Wenjuan Song,&nbsp;Mohammad Yazdani-Asrami","doi":"10.1016/j.supcon.2025.100173","DOIUrl":"10.1016/j.supcon.2025.100173","url":null,"abstract":"<div><div>The utilization of superconductors in modern aviation, power and energy, space, healthcare, and quantum sectors offers substantial advantages, including significant energy savings, higher reliability, lower CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> emissions, higher efficiencies, and increased power densities. However, the quench phenomenon – transition from superconducting state to normal state – presents a major challenge, particularly in high temperature superconductors (HTSs), and especially in sensitive applications including fusion energy and aviation sectors. Most of the existing quench detection systems, i.e., conventional techniques, simply work based on threshold, and therefore, they have challenges being inflexible, non-intelligent, slow, and with the potential of missing quench or raising false alarm. This study proposes an advanced quench diagnostic technique aiming at enhancing reliability of HTS devices. This diagnostic technique quantifies quench events by analyzing the ratio of a selected harmonic component’s amplitude, including the second to ninth harmonics, to that of the fundamental frequency in voltage measurement. Fast Fourier Transform (FFT) is employed to analyze the frequency-domain characteristics of voltage signals in both quench and non-quench stages. Amplitudes of the main harmonic frequencies were measured in the spectrum and calculated the harmonic amplitude ratio. Principal Component Analysis (PCA) was applied to reduce dimensionality and extract the most relevant features associated with quench events. The original 17 harmonic ratio features were transformed into three principal components per label, preserving essential information of the dataset for classification. The Support Vector Machine (SVM) was used as an automatic intelligent decision-making technique to discriminate new cases of quench from non-quench condition. Finally, after continuous optimization of the PCA and SVM model, this novel approach, based on experimental data, demonstrated to reach an accuracy of 100% and promised a fast, more flexible, and reliable method for quench diagnostics. In addition, to validate and demonstrate the generalizability of the proposed quench detection method, this diagnostic technique was tested for a totally new HTS coil sample with different type, configuration, and turns number, which high discrimination accuracy was observed. This is a real testimony to the effectiveness of the proposed technique which is robust and generalized. However, further tests on larger and more diverse datasets are underway to accelerate its future applicability in fusion, electric transportation, and renewable energy sectors.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100173"},"PeriodicalIF":5.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144229664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave surface resistance in MgB2: Effect of Te and cubic-BN addition on flux flow and pinning","authors":"Andrea Alimenti ,&nbsp;Enrico Silva ,&nbsp;Kostiantyn Torokhtii ,&nbsp;Pablo Vidal García ,&nbsp;Petre Badica ,&nbsp;Adrian Crisan ,&nbsp;Mihai Alexandru Grigoroscuta ,&nbsp;Nicola Pompeo","doi":"10.1016/j.supcon.2025.100170","DOIUrl":"10.1016/j.supcon.2025.100170","url":null,"abstract":"<div><div>MgB<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is a perspective superconductor for many power applications. How this potential refers also to microwave or radiofrequency applications is still to be determined. Although its ultimate surface resistance in zero field is not competitive with conventional metallic superconductors, its strong pinning properties can favor RF applications in a dc magnetic field. Nonetheless, the RF response in the vortex state has been relatively less studied, as well as the effect of artificial pinning centers on the microwave surface resistance in the mixed state. In this paper we study the surface resistance of spark-plasma-sintered MgB<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, with and without Te and cubic-BN (cBN) addition, in a dc magnetic field up to 1.2 T. We summarize previous results on pure MgB<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and we present new data on Te- and cBN- added MgB<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. We use a two-tone dielectric-loaded resonator to measure the field-dependent surface resistance at 16.5 and 26.7 GHz in the temperature range from 10 K to <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>. By exploiting the simultaneous measurements at two frequencies, we extract the flux-flow resistivity, the pinning constant <span><math><msub><mrow><mi>k</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> and the depinning frequency <span><math><msub><mrow><mi>f</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>. The two-band nature of MgB<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> affects the field dependence of the flux-flow resistivity. The microscopic superconducting state is not affected by the addition of artificial pinning centers, indicating that Te and cBN do not affect interband or intraband scattering. Pinning shows a measurable trend towards an increase in the Te- and cBN- added samples at higher temperatures and fields. We finally compare the results to those obtained in bulk Nb<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>Sn, also in view of possible in-field RF applications such as microwave cavity-based haloscopes.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100170"},"PeriodicalIF":5.6,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite element approach for calculating stress distribution in non-circular high-temperature superconducting coils","authors":"Zhihua Li ,&nbsp;Li Lu ,&nbsp;Zhuoyan Zhong ,&nbsp;Wei Wu","doi":"10.1016/j.supcon.2025.100168","DOIUrl":"10.1016/j.supcon.2025.100168","url":null,"abstract":"<div><div>Complex stress distribution arises in high-temperature superconducting (HTS) coil based on REBCO coated conductors, which is affected by the applied winding tension, thermal stress during cooling down, and electromagnetic forces when energizing the coil. The material and structure of bobbin and overband also play an important role.</div><div>In this study, a finite element (FE) method model was proposed for analyzing the stress of HTS coils with non-circular geometries, especially the stresses arise from winding tension and overband. Compared to traditional analytical methods, this approach is not only applicable to circular coils but also to coils of other shapes, such as racetrack and D-shape coils that could hardly be calculated analytically. Comparison between the traditional analytical model and the proposed FE method model was obtained, which validated the latter one according to the simulation results on the radial and hoop stresses of two circular coils. Next, the proposed approach was used to analyze the stress distribution of a racetrack coil and a D-shaped coil. Furthermore, a comprehensive analysis of the stress distributions in the epoxy impregnated racetrack coil and the D-shaped coil was conducted, considering winding stress, thermal stress, electromagnetic stress, and the influence of overband. Finally, we calculated the winding stress in the racetrack coil considering nonlinear compressive behaviors. The results show that the stress distributions are quite different from the case that not considering compressibility.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100168"},"PeriodicalIF":5.6,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-band superconductivity in intercalated rhombohedral ZrNCl","authors":"Zhenkai Xie ,&nbsp;Ziheng Sun ,&nbsp;Xinmin Wang ,&nbsp;Junying Shen ,&nbsp;Liyuan Zhang","doi":"10.1016/j.supcon.2025.100169","DOIUrl":"10.1016/j.supcon.2025.100169","url":null,"abstract":"<div><div>The multiband superconductor offers a unique venue for investigating the interplay between Cooper pairing and inter-band interactions. Here we report the emergence of two-band superconductivity in hybridized superlattice Na<span><math><msub><mrow></mrow><mrow><mi>0.1</mi></mrow></msub></math></span>(1,3-diaminopropane)<span><math><msub><mrow></mrow><mrow><mi>0.25</mi></mrow></msub></math></span> ZrNCl. The intercalation of organic molecules and Na ions into the interlayer modulates the electronic structure near the Fermi surface, and promotes the emergence of intrinsic superconductivity with onset transition temperature <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>15</mn></mrow></math></span> K. Systematical investigations of upper critical field <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>c2</mi></mrow></msub></math></span> reveals that temperature dependence of <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>c2</mi></mrow></msub></math></span> can be well-described by two-band theory, yielding the out-of-plane and in-plane <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>c2</mi></mrow></msub></math></span> values of 2.9 T and 11.5 T, respectively. Furthermore, analysis of the reversible magnetization data confirms the intrinsic two-band characteristics, which deviate significantly from the predictions of the single-band Ginzburg–Landau(GL)model. Meanwhile, the superconducting state exhibits a two-fold rotational symmetry under in-plane magnetic fields, contrasting with the three-fold symmetric ZrNCl lattice. Angle-dependent <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>c2</mi></mrow></msub></math></span> behavior aligns with the three-dimensional (3D) anisotropic GL model. These findings establish the intercalated rhombohedral ZrNCl as a compelling platform for exploring multiband superconductivity.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100169"},"PeriodicalIF":5.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Split pulsed magnet combining high peak central magnetic field and long rise time for pulsed field magnetization of high temperature superconductors","authors":"Juntong Hu ,&nbsp;Wenjiang Yang ,&nbsp;Difan Zhou ,&nbsp;Peng Zhao ,&nbsp;Mingliang Bai ,&nbsp;Juzhuang Yan ,&nbsp;Haoran Jiang ,&nbsp;Tianxin Lan","doi":"10.1016/j.supcon.2025.100166","DOIUrl":"10.1016/j.supcon.2025.100166","url":null,"abstract":"<div><div>Split pulsed magnets are widely employed in high temperature superconducting (HTS) motor armature winding as magnetizing coils to implement in-situ pulsed field magnetization (PFM) for HTS field pole magnets. We have designed and developed a compact and portable split pulsed magnet, that balances a peak central magnetic field of nearly 7 T and a rise time of 24 ms, making it particularly suitable for PFM of HTS materials at lower temperatures. Single and two-step PFM experiments of HTS GdBa ₂Cu₃O<span><math><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>δ</mi></mrow></msub></math></span> (GdBCO) bulk in different temperature ranges are conducted and the maximum trapped fields <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> are observed to be <span><math><mrow><mo>&gt;</mo><mn>3</mn></mrow></math></span> T in the 40–50 K temperature range and nearly 4 T at 30 K in a 30 mm diameter GdBCO bulk. The trapped field results validate the excellent PFM ability of this designed split pulsed magnet and indicate a high trapped field (close to 4 T) can also be obtained in a coreless double armature. Moreover, multi-physical field responses of the split pulsed magnet during discharge are analyzed by a 3D field-circuit coupling model, which manifests that the split pulsed magnet is in a stable and safe operating state even under the highest charge voltage. Finally, this study may provide a novel clue for the development of coreless HTS bulk motors and suggest that HTS coreless motors can maintain a high air gap magnetic field while avoiding losses and thrust or torque fluctuations caused by iron core saturation under high magnetic fields.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100166"},"PeriodicalIF":5.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}