Physica C-superconductivity and Its Applications最新文献

Holographic Schwinger–Keldysh effective field theories including a non-hydrodynamic mode

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-29 DOI: 10.1016/j.physc.2025.1354701

Yan Liu , Ya-Wen Sun , Xin-Meng Wu

引用次数: 0

Origin of the reentrant tetragonal phase in hole-doped Fe-pnictide superconductors: Role of intersite Coulomb interaction

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-22 DOI: 10.1016/j.physc.2025.1354699

Hao Luo, Huan Li, Xing Ming, Xiao-Jun Zheng

{"title":"Origin of the reentrant tetragonal phase in hole-doped Fe-pnictide superconductors: Role of intersite Coulomb interaction","authors":"Hao Luo, Huan Li, Xing Ming, Xiao-Jun Zheng","doi":"10.1016/j.physc.2025.1354699","DOIUrl":"10.1016/j.physc.2025.1354699","url":null,"abstract":"<div><div>Using mean-field approaches within the extended five-orbital Hubbard model, we reveal that intersite Coulomb interactions play a crucial role in determining the distinct magnetic phases of iron-based superconductors. We demonstrate that the reentrant tetragonal (<span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>) phase, which is a spin charge density wave (SCDW) phase, is a combination of the stripe-like antiferromagnetic phase (str-AFM) and the charge density wave (CDW) phase. We prove that SCDW is the ground state in the hole-doped Fe-pnictides as long as the intersite Coulomb interaction (<span><math><mi>V</mi></math></span>) increases with doping concentration. Our work not only provides a numerical realization of the reentrant <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> state but also emphasizes the significant role of intersite interactions in the emergence of this phase, offering a deep understanding into the complex diagram phase of iron-based materials.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354699"},"PeriodicalIF":1.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Superconducting correlations in the asymmetric Hubbard model

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-18 DOI: 10.1016/j.physc.2025.1354693

Pavol Farkašovský

{"title":"Superconducting correlations in the asymmetric Hubbard model","authors":"Pavol Farkašovský","doi":"10.1016/j.physc.2025.1354693","DOIUrl":"10.1016/j.physc.2025.1354693","url":null,"abstract":"<div><div>The projector Quantum-Monte-Carlo method is used to examine effects of down-spin electron hopping <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>↓</mi></mrow></msub></math></span> and the on-site interaction <span><math><mi>U</mi></math></span> between the up and down spin electrons on superconducting correlations in the two-dimensional asymmetric Hubbard model. It is shown that both, the down-spin electron hopping, as well as the on-site interaction strongly enhance the superconducting correlations in the <span><math><mi>d</mi></math></span>-wave channel. The most significant enhancement of superconducting correlations, by down-spin electron hopping, is found for electron concentrations near the half-filled band case where, in addition, the strong connection between the diagonal charge stripes and the superconducting correlations is observed and the increasing on-site interaction <span><math><mi>U</mi></math></span> further enhances this effect. The enhancement of superconducting correlations is observed also in the axial striped phase, while it is negligible in the segregated phase. This opens new route to understanding the relation between the inhomogeneous charge ordering and superconductivity in strongly correlated electron systems.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354693"},"PeriodicalIF":1.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal transmittance measurements of niobium at cryogenic temperatures 铌在低温下的热透射率测量结果

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2025.1354694

Marc Wenskat , Leon King , Lasse Koch , Cem Saribal , Anton Lorf , Isabel González Díaz-Palacio , Cornelius Martens , Robert Zierold , Wolfgang Hillert

{"title":"Thermal transmittance measurements of niobium at cryogenic temperatures","authors":"Marc Wenskat , Leon King , Lasse Koch , Cem Saribal , Anton Lorf , Isabel González Díaz-Palacio , Cornelius Martens , Robert Zierold , Wolfgang Hillert","doi":"10.1016/j.physc.2025.1354694","DOIUrl":"10.1016/j.physc.2025.1354694","url":null,"abstract":"<div><div>The first <span><math><mi>O</mi></math></span>(100snm) of the inner surface Niobium-based superconducting RF (SRF) cavities are crucial to achieve high accelerating fields and a low surface resistance. Recent treatments aim to improve superconducting properties by tailoring the interstitial atom concentration or by depositing thin superconducting films. Yet, no investigation of the thermal characteristics of those surfaces after such treatments has been done, although this is a crucial property to cool the induced RF losses away and to maintain the superconducting state while high surface magnetic fields are applied. In this contribution, a newly developed experimental set-up is described, which allowed the first ever measurement of the thermal transmittance of Mid-T heat treated and Superconductor-Insulator-Superconductor (SIS) coated niobium samples. The results show that the SIS samples perform the same as standard niobium and that Mid-T heat treated samples have an improved thermal transmittance of 30%.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354694"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of temperature and spinning speed on texture in spin-coated Sm2Zr2O7 buffer layer on Ni-5 at.%W RABiTS for coated conductors

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2025.1354669

M. Nandana Nandakumar , Rahul Raj , M.S. Ramachandra Rao , Deepak Kumar , Satyam Suwas , N. Harish Kumar

{"title":"Effect of temperature and spinning speed on texture in spin-coated Sm2Zr2O7 buffer layer on Ni-5 at.%W RABiTS for coated conductors","authors":"M. Nandana Nandakumar , Rahul Raj , M.S. Ramachandra Rao , Deepak Kumar , Satyam Suwas , N. Harish Kumar","doi":"10.1016/j.physc.2025.1354669","DOIUrl":"10.1016/j.physc.2025.1354669","url":null,"abstract":"<div><div>The usage of Rolling Assisted Biaxially Textured Substrates (RABiTS) is a versatile method to produce High-Temperature Superconductor (HTS) based coated conductors. We have investigated, for the first time, the texture evolution of the Sm<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> (SZO) barrier layer produced by spin coating on Ni-5 at.%W (Ni5W) RABiTS to create a biaxially textured buffer layer architecture. The annealing temperature and spinning speed which are the important film deposition parameters, were varied and their effect on the texture of the film has been investigated to obtain the optimum conditions required for the growth of highly textured film with sufficient thickness. Textured growth of SZO film could be seen across a wide range of substrate temperatures by X-ray diffraction (XRD) based studies. The microstructural investigations were executed using a Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). The findings indicate that the annealing temperature and spinning speed affect the films' growth orientation and surface morphology. The XRD (φ scan and ω scan) studies have shown the ability to realise the SZO buffer layer with strong in-plane and out-of-plane texture and a c-axis oriented growth on Ni5W substrate by chemical solution deposition (CSD).</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"631 ","pages":"Article 1354669"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of winding pitches on dynamic resistance of CICC made from CORCs

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2025.1354681

Liguang Hu , Xuhui Xu , Bibo Zhou , Xian Chen , Qi Cheng , Bangzhu Wang , Junhua Cheng

{"title":"Effect of winding pitches on dynamic resistance of CICC made from CORCs","authors":"Liguang Hu , Xuhui Xu , Bibo Zhou , Xian Chen , Qi Cheng , Bangzhu Wang , Junhua Cheng","doi":"10.1016/j.physc.2025.1354681","DOIUrl":"10.1016/j.physc.2025.1354681","url":null,"abstract":"<div><div>The second generation (2G) high temperature superconducting (HTS) REBCO tapes, presently a unique possible candidate for use in future large high field magnets above 25 T, are promising choice for high capacity current cable-in-conduit conductor (CICC) used in large high field magnets of fusion and power transmissions. Generally, HTS based CICCs are made from several HTS cables or strands consisting of individual REBCO tapes. A configuration of CICC is proposed, which is made from six conductor on round core cables (CORCs) with symmetrically helical winding on a petal copper former. The cooling medium flows in central channels of former and six CORCs, respectively. Although the CICCs generally operate in DC mode, they inevitable endure AC influence at least in charging and discharging process or even ripple current. Consequently, the dynamic resistance appears, which not only generates additional AC loss but also importantly causes nonuniform current distribution and instability. This paper employs analytical model and numerical simulations to investigate the dynamic resistance characteristics of CORC and CICC conductors with different winding pitches respectively. An analytical model is established based on the rotating magnetic field method to efficiently compute the dynamic resistance of single-layer CORC and CICC. Subsequently, three-dimensional (3D) models of CORC and CICC with different winding pitches are established. Using finite element method, the influence of winding pitches on dynamic resistance are calculated based on the T-A formulation. Numerical simulation results are consistent with analytical calculations, demonstrating that winding pitch has a significant impact on dynamic resistance. This study can provide valuable reference for the design of large-scale high field magnets.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"631 ","pages":"Article 1354681"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantum criticality of type-I and critically tilted Dirac semimetals

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2025.1354687

Huanzhi Hu , Frank Krüger

{"title":"Quantum criticality of type-I and critically tilted Dirac semimetals","authors":"Huanzhi Hu , Frank Krüger","doi":"10.1016/j.physc.2025.1354687","DOIUrl":"10.1016/j.physc.2025.1354687","url":null,"abstract":"<div><div>We investigate the universality of an Ising symmetry breaking phase transition of tilted two-dimensional Dirac fermions, in the type-I phase as well as at the Lifshitz transition between a type-I and a type-II semimetal, where the Fermi surface changes from point-like to one with electron and hole pockets that touch at the overtilted Dirac cones. We compute the Landau damping of long-wavelength order parameter fluctuations by tilted Dirac fermions and use the resulting IR propagator as input for a renormalisation-group analysis of the resulting Gross–Neveu–Yukawa field theory. We first demonstrate that the criticality of tilted type-I fermions is controlled by a line of fixed points along which the poles of the renormalised Green function correspond to an untilted Dirac spectrum with varying anisotropy of Fermi velocities. At the phase transition the Lorentz invariance is restored, resulting in the same critical exponents as for conventional Dirac systems. The multicritical point is given by the endpoint of the fixed-point line. It can be approached along any path in parameter space that avoids the fixed point line of the critical type-I semimetal. We show that the critical exponents at the Lifshitz point are different and that Lorentz invariance is broken.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354687"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical approach to calculating binding requirements in high-field STM superconducting magnets

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2025.1354670

Zhipeng Jiang , Hang Zhao , Lei Yu , Yuyang Shi , Jianyuan Xu , Zhipeng Xu , Yue Qi , Zhiyou Chen , Hangwei Ding , Pengcheng Huang , Wenge Chen

{"title":"Numerical approach to calculating binding requirements in high-field STM superconducting magnets","authors":"Zhipeng Jiang , Hang Zhao , Lei Yu , Yuyang Shi , Jianyuan Xu , Zhipeng Xu , Yue Qi , Zhiyou Chen , Hangwei Ding , Pengcheng Huang , Wenge Chen","doi":"10.1016/j.physc.2025.1354670","DOIUrl":"10.1016/j.physc.2025.1354670","url":null,"abstract":"<div><div>With advancing demands in frontier science, maximizing both the magnetic field strength and diameter of superconducting magnets has become increasingly significant. However, as these parameters grow, the complexity of mechanical analysis for the magnet intensifies. Enhancing the structural stability of superconducting magnets through binding wires is a crucial challenge. Therefore, this paper proposes a numerical method to determine the requirements of binding layers. The finite element numerical method was used to comprehensively analyze the stress generated during the winding, cooling, and excitation of the 12T STM superconducting magnet being developed by the High Magnetic Field Laboratory of China (CHMFL). The required winding forces and number of binding layers for the magnet was determined, effectively improving spatial utilization and preventing shifts or quenching through elasticity theory. This method may also be applied broadly to the mechanical analysis and binding layer determination of other large-aperture, high-field superconducting magnets.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"631 ","pages":"Article 1354670"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced mechanical load limit of CORC cable under transverse compression and axial tensile loads

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2025.1354682

Jiangtao Yan , Zhicai Ma , Yuanwen Gao

{"title":"Enhanced mechanical load limit of CORC cable under transverse compression and axial tensile loads","authors":"Jiangtao Yan , Zhicai Ma , Yuanwen Gao","doi":"10.1016/j.physc.2025.1354682","DOIUrl":"10.1016/j.physc.2025.1354682","url":null,"abstract":"<div><div>The winding core of CORC (conductor on round core) cables is crucial for resisting mechanical deformations. While different winding core structures can influence the maximum load capacity of these cables, the specific impact of changes in the winding core structure on the mechanical properties of superconducting cables remains unclear. This paper establishes 3D mechanical models of CORC type cables, especially realizes the modeling of the interlocking core structure for the first time and analyzes the mechanical behaviors of these cables under transverse compression and axial tensile loads. It discusses the effects of the winding core structure and the number of inner copper tapes between the winding core and the high-temperature superconducting tape on the mechanical load limits of CORC cables. The results show that CORC cables exhibit enhanced performance in transverse compression and axial tension when a tube core is used for transverse loads and a spiral core for axial loads. The axial strain of the superconducting layer increases as the number of inner copper tapes increases in the transverse compression case, and it decreases as the number of inner copper tapes increases under axial tensile loading. Furthermore, the effect of an arc load block structure on the transverse compression performance of CORC cables is also investigated. The results reveal that the optimal contact angle for achieving optimal transverse compression performance in CORC cables with an arc block structure is approximately 5°. The decrease in the current-carrying capacity of cables in the arc block structure is mainly caused by the combination of compressive strain at the contact area and tensile strain at the contact edges. The numerical results can provide a basis for the reasonable selection of the structure of coil former when the winding CORC coil magnet.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"631 ","pages":"Article 1354682"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interfacial superconductivity in Cu/Cu2O and its effect on shielding ambient electric fields

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-03-12 DOI: 10.1016/j.physc.2024.1354600

Dale R. Harshman , Anthony T. Fiory

{"title":"Interfacial superconductivity in Cu/Cu2O and its effect on shielding ambient electric fields","authors":"Dale R. Harshman , Anthony T. Fiory","doi":"10.1016/j.physc.2024.1354600","DOIUrl":"10.1016/j.physc.2024.1354600","url":null,"abstract":"<div><div>A model is presented for two-dimensional superconductivity at semiconductor-on-metal interfaces mediated by Coulomb interactions between electronically-active interface charges in the semiconductor and screening charges in the metal. The junction considered is native Cu<sub>2</sub>O on Cu in which an interfacial double charge layer of areal density <em>n</em>, comprising superconducting holes in Cu<sub>2</sub>O and mediating electrons in Cu, is induced in proportion to a sub-monolayer of adsorbed <sup>4</sup>He atoms. Evidence for superconductivity on copper with prior air exposure is revealed in new analysis of previously published work function data. Based on a theory developed for layered superconductors, the intrinsic transition temperature <em>T</em><sub>C</sub> = β <em>n</em><sup>1/2</sup>/ζ is determined by <em>n</em> and transverse distance ζ ≃ 2.0 Å between the charge layers; β = 1.933(6) <em>e</em><sup>2</sup>ƛ<sub>C</sub>/<em>k</em><sub>B</sub> = 1247.4(3.7) K-Å<sup>2</sup> is a universal constant involving the reduced Compton wavelength of the electron ƛ<sub>C</sub>. This model is applied to understanding the shielding of copper work-function patch and gravitational compression electric fields reported in the Witteborn-Fairbank gravitational electron free fall experiment. Interfacial superconductivity with <em>n</em> ≃ 1.6 × 10<sup>12</sup> cm<sup>−2</sup>, <em>T</em><sub>C</sub> ≃ 7.9 K and Berezinskiĭ-Kosterlitz-Thouless temperature <em>T</em><sub>BKT</sub> ≃ 4.4 K accounts for the shielding observed at temperature <em>T</em> ≃ 4.2 K. Helium desorption and concomitant decreases in <em>n</em> and <em>T</em><sub>C</sub> replicate the temperature transition in ambient electric fields on falling electrons, as observed by Lockhart et al., and the vanishing of superconductivity above <em>T</em> ≃ 4.8 K.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354600"},"PeriodicalIF":1.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0