Up to now, the highest current densities of MgB2 superconducting wires have been obtained by the internal magnesium diffusion (IMD) method. MgB2 superconductors are especially suitable for DC or AC windings generating low or medium magnetic fields, where thermal stability and low AC losses are important issues. Mechanical, thermal and electrical parameters of the wires are strongly influenced by metallic

Dry magnets using high temperature superconductors and MgB2 are attractive options to depart from dependence on liquid helium in MRI scanners. In the dry magnets, however, lack of thermal mass of cryogen makes a controlled quench difficult and extends time for restarting the magnets after the quench. In this study, a novel rapid ramp-down procedure, which can be substituted for the controlled quench

Superconducting nanowire single-photon detectors (SNSPDs) wherein ultrathin films are fabricated on Si substrates are greatly affected by lattice mismatch between the thin film and the substrate. A buffer layer can be used to reduce such lattice mismatch or optimize the strain in the film, thereby improving device performance. We prepared and optimized Nb5N6 as a buffer layer and found that it considerably

Majorana bound states (MBSs) are spatially-localized zero-energy quasiparticles following non-Abelian braiding statistics that hold a great promise for fault-tolerant topological quantum computing. Different platforms have been designed to realize the MBSs in condensed matter, including semiconducting nanowire in proximity to conventional superconductors, superconductor-topological insulator layered

Resistivity, magnetoresistance, and upper critical field, have been comprehensively studied for the bismuth (Bi)-III superconducting phase in the pressure range of 2.9 GPa ⩽ P⩽ 6.2 GPa. It is discovered that the transition temperature T c of the Bi-III phase is gradually suppressed with increasing pressure. Strikingly, the temperature-dependent resistivity above T c in the Bi-III region reveals notable

One of the features of the unconventional state in iron-based superconductors is possibility to transform to the s ++ state with the increase of the nonmagnetic disorder. Detection of such a transition would prove the existence of the state. Here we study the temperature dependence of the London magnetic penetration depth within the two-band model for the and s ++ superconductors. By solving Eliashberg

Low-temperature sintering to fabricate MgB2 is considered a promising method because it reduces the formation of MgO and reduces the grain size, thereby increasing the critical current density. Chemical doping, ball milling of precursor and modifying the Mg source in precursor for low-temperature sintering have all been carefully investigated. However, the threshold of sintering temperature have been

The aim of this article is to present a three-dimensional (3D) simulation based on Voronoi tessellation, used to assess the strain dependence of the superconducting critical properties of inhomogeneous polycrystalline Nb3Sn at the microstructural level. To support this objective, we first present a polycrystalline model with equiaxed grains used to analyze the relationship between the polycrystalline

The dynamics of large superwavelength open systems which are free-standing multi-wire lines with a large number of Josephson junctions, DC bias batteries and other lumped elements is analyzed using direct numerical simulation. Such systems represent the simplest version of the active Josephson antennas proposed in our earlier studies and show promise as terahertz and subterahertz radiation sources

Rare earth barium copper oxide (REBCO) coated conductor has emerged as one of the high T c superconductors suitable for future ultrahigh field superconducting magnet applications. In the design and fabrication of such ultrahigh field REBCO magnets, it is essential to understand the behavior of REBCO coated conductor. The effect of heating on the properties of commercial REBCO coated conductors is very

We report herein the development of a superconducting nanowire single-photon detector (SNSPD) that uses a hybrid cryocooler compatible with space applications. The hybrid cryocooler incorporates a two-stage high-frequency pulse-tube cryocooler and a Joule–Thomson loop, which produces a minimum temperature of 2.2 K. The SNSPD with the structure of sandwiched nanowires integrated in the cryocooler shows

Both the pancake coiling and conductor on round core (CORC) cabling processes consist of winding second-generation high-temperature superconducting tape (REBCO) in a core. The contact behavior between the tape and the core during the winding process directly affects the critical current, cable flexibility, mechanical support and electrical contact resistance. Therefore, the winding process needs to

Detailed simulation can play a fundamental role in the design, manufacture, and operation of high-field magnets. This study introduces a new equivalent circuit simulation method for the no-insulation (NI) superconducting magnet. The refined circuit model (RCM) can describe the current distribution inside the REBa2Cu3O7-δ (RE, rare earth elements) tapes in the equivalent circuit model. A single turn

Fujikura Ltd has developed production techniques of REBa2Cu3O X (REBCO, RE = rare earth) coated conductors (CCs) using large-area ion-beam-assisted-deposition and hot-wall type pulsed-laser-deposition. We have provided high-performance REBCO CCs with long length and high homogeneity of critical current. The CCs are required to maintain their superconducting properties under mechanical stresses for

Superconducting nanowire single-photon detectors (SNSPDs) made of ultrathin δ-NbN films have been widely applied in both visible and infrared wavelengths. For mid-infrared (MIR) wavelengths, SNSPDs made of tungsten silicide films with a lower critical temperature were reported up to 9.9 μm wavelength. In this study, we demonstrate the potential of NbN-SNSPDs for use in MIR applications. SNSPDs made

We report for the first time the occurrence of superconductivity in the quaternary silicide carbide YRe2SiC with T c ≈ 5.9 K. The emergence of superconductivity was confirmed by means of magnetic susceptibility, electrical resistivity, and heat capacity measurements. The presence of a well-developed heat capacity feature at T c confirms that superconductivity is a bulk phenomenon, while a second feature

We measured 1H nuclear magnetic resonance (NMR) spectra from silicon rubber in a magnetic field trapped by a compact tubular MgB2 superconductor bulk magnet (60 mm outer diameter, 40 mm inner diameter, and 60 mm height) which was magnetized by field-cooled magnetization from an applied field, , of 0.4778 T at 20 K. The sharpest 1H NMR spectrum of the resonant frequency, , of 20.314 MHz, which corresponded

In many high-temperature superconducting (HTS) applications, HTS coated conductors carry DC currents under external AC magnetic fields. There are two AC loss mechanisms in this situation: magnetization loss due to the external magnetic field and dynamic loss due to the interaction between the DC current and the external magnetic field. The sum of these two loss components is referred to as total loss

We have investigated the superconducting transition temperature T c depression and magnetic-field-induced quantum critical behavior in three-dimensional (3D) polycrystalline niobium (Nb) films. For superconducting films with 26.8 nm 72.9 nm, the T c value increases from ∼4.94 to ∼8.74 K. Through comparing our experimental data with proximity effect and weak localization effect, the T c depression can

A high-temperature superconducting no-insulation (NI) coil, with its self-protection property, high engineering current density and unique demagnetization property, becomes a potential candidate for an electrodynamic suspension (EDS) system. Compared with the applications in high field magnets, the NI coil used in the EDS system is considered as working in a dynamic state, the magnetization loss generated

A model of high-temperature superconducting dynamos, a promising type of flux pump capable of wireless injection of a large DC current into a superconducting circuit, has recently been chosen as an applied superconductivity benchmark problem and solved using ten different numerical methods (Ainslie et al 2020 Supercond. Sci. Technol. 33 105009). Using expansions in Chebyshev polynomials for approximation

Nb deposited by magnetron sputtering onto hot Cu-15 wt.%Sn bronze substrates at temperatures above 700 C achieved Nb3Sn film growth at a rate of 33 nm min−1, which was an order of magnitude faster than that achieved for deposition of Nb on bronze at low temperature followed by in situ post reaction at the same high temperatures. Tin content in the Nb3Sn films made on hot bronze was ∼26.3%, which is

High quality FeSe0.5Te0.5 (FST) epitaxial thin films were successfully prepared on SrTiO3 (STO), MgO and LaAlO3 substrates with a TiO2 buffer layer by pulsed laser deposition method, respectively. We present the results of a collaborative study on the superconducting and magnetic properties of the three types films, such as the critical temperature T c, the anisotropy, and the critical current density

In superconducting radiofrequency accelerating cavities for particle accelerators, the Nb/Cu structure is one of the alternatives to bulk Nb but R&D is required to achieve a reproducible performance that competes with bulk Nb. The DC entry field H en and critical temperature were studied in the thin Nb films deposited by magnetron sputtering on Cu substrate. The Nb surfaces were further treated by

This paper presents experimental results on a quench of an intra-layer no-insulation (LNI) (RE: rare earth)Ba2Cu3O7−δ (REBCO) coil in a 31.4 T central magnetic field and simulated results on the quench. We have been designing a persistent-mode 1.3 GHz (30.5 T) nuclear magnetic resonance (NMR) magnet with a layer-wound REBCO inner coil. Protection of the REBCO coil from quench is a significant issue

Room-temperature optical constants of crystalline Bi2Sr2CaCu2O were determined using data extracted from Brillouin light scattering spectra. Optical extinction coefficient-to-refractive index ratios at a wavelength of 532 nm were obtained from bulk phonon peak linewidth and frequency shift measurements and range from for directions close to the crystallographic c-axis. These ratios, and optical extinction

We fabricated a compact (13 12 12.5 mm3) trapped-field magnet by stacking 200 pieces of EuBa2Cu3O7 coated conductors (CCs) with BaHfO3 nanorods as artificial pinning centers. It was magnetized by field-cooling method using a 18 T superconducting magnet, and the maximum field of 14.8 T was trapped at 10 K at a field-ramp rate of 0.1 T min−1. At higher temperatures, although the trapped field was decreased

In this paper, we theoretically study superconductivity in hydrogenated penta-graphene (HPG). HPG has thermodynamical, mechanical and structural stability. By decreasing the Fermi energy of HPG, both manually and p-doping, we get strong density of states at the Fermi level. Therefore, one could expect that decreasing the Fermi energy may increase the superconducting transition temperature similar to

We demonstrate and verify quantum detector tomography of a superconducting nanowire single-photon detector (SNSPD) in a multiplexing scheme which permits measurement of up to 71 000 photons per input pulse. We reconstruct the positive operator valued measure (POVM) of this device in the low photon-number regime, and use the extracted parameters to show the POVMs spanning the whole dynamic range of

Critical temperature, T c, and transition width, ΔT c, are two primary parameters of the superconducting transition. The latter parameter reflects the superconducting state disturbance originating from the thermodynamic fluctuations, atomic disorder, applied magnetic field, the presence of secondary crystalline phases, applied pressure, etc. Recently, Hirsch and Marsiglio (2021 Phys. Rev. B 103 134505

In order to reliably make use of superconductors in wind generators, a double-stator superconducting flux modulation generator is proposed here to avoid rotation of field coils and armature windings. The superconducting field coils are located in the inner stator while the armature windings are placed in the outer stator. In this way, the stationary-rotatory couplings of current and cryogenic coolants

Canted cosine theta (CCT) magnets have received increased attention in the recent years due to their inherent characteristics of high field quality and low conductor stresses, as each turn is supported by the metallic former. CCT geometry is suitable for complex magnets—such as nested dipoles, which allow full 360 control of the magnetic field direction. Modeling and design of such magnets is the subject

Bulk (RE)-Ba-Cu-O [(RE)BCO] cuprate HTS have been developed steadily towards a wide range of sustainable engineering and technological applications since their discovery in 1986 based primarily on their unique potential to trap very large magnetic fields (>5 T) at temperatures that are accessible potentially by thermo-electric cooling techniques. Trapped fields of ∼10 T at the surface of individual

We investigated local magnetic flux biasing (LFB) that induces a phase shift in superconductor circuits by locally applying a magnetic field through the superconductor loop with Josephson junctions. The arbitrary phase shift can be achieved using LFB without modifying the circuit fabrication process. To quantitatively evaluate the effects of introducing LFB for practical superconductor circuit applications

High-temperature superconducting coated conductors (CCs) are considered an enabling ultra-high field (UHF) tape-conductor technology due to their extremely high engineering current densities at very high magnetic fields and low temperatures, and high mechanical strength. A major challenge is however related to induction of problematically large superconducting screening currents (as an effect of the

FeSe1−x Te x superconductors manifest some intriguing electronic properties depending on the value of x. In FeSe single crystal, the nematic phase and Dirac band structure have been observed, while topological surface superconductivity (SC) with the Majorana bound state was found in the crystal of x∼ 0.55. Therefore, the electronic properties of single crystals with 0 < x ⩽ 0.5 are crucial for probing

In the study of high temperature superconducting maglev, the analysis of the forces acted on a high temperature superconductor (HTS) bulk is a basic issue, which can directly reflect the levitation and guidance performances of an HTS maglev system. In previous studies, the electromagnetic guideway was verified to be an alternative guideway type for HTS maglev. Recently, we carried out experimental

The paper is devoted to several recent rather fundamental achievements in the field of superconducting nanostrip single-photon detectors which make an impact on understanding the detection mechanism, technological challenges and performance metrics important for applications. Special attention is given to static and temporal fluctuations of different origin affecting key metrics of these detectors

Here we propose a new approach capable of calculating the hysteresis loss of 3D HTS coil models based on the modeling framework of the multi-scale method. The study enhances the multi-scale method for 2D simulations by introducing the homogenization technique to simplify the topological features of coils’ cross sections. With the simplification, a 3D A-formulation magnetostatic model is built for magnetic

Ternary noncentrosymmetric superconductors TaXSi (X = Re, Ru) investigated by magnetization, resistivity, and specific heat measurements. It crystallize in the orthorhombic TiFeSi-type structure with superconducting transition = 5.32 K and 3.91 K for TaReSi and TaRuSi, respectively. A low value of specific heat jump and the upper critical field concave nature suggests a nontrivial superconducting gap

We studied magnetic levitation forces for bulk superconductors through numerical analysis. We virtually varied the superconducting junctions between domains formed through multiple seeding (four seeds) and investigated the effect of the following parameters on the magnetic levitation force: (1) the critical current density J c across grain boundaries (GBs) or superconducting junctions between crystal

The High Luminosity Large Hadron Collider (HL-LHC) is the new flagship project of CERN. First endorsed in 2013 and approved in 2016, HL-LHC is an upgrade of the accelerator aiming to increase by a factor of ten the statistics of the LHC collisions at the horizon of 2035–2040. HL-LHC relies on cutting edge technologies: among them, large aperture superconducting magnets will replace the present hardware

In this work, we have verified experimentally an all-(RE)BaCuO hybrid trapped field magnet lens (HTFML) using only one cryocooler and a special technique named the ‘loose contact method’. In the experimental setup, only the inner magnetic lens was tightly connected to the cold stage and cooled at all times, and the outer trapped field magnet (TFM) cylinder was loosely connected to the cold stage before

We report the strong dependence of critical current density (J c) on the sample thickness (d) along the crystalline c-axis in CaKFe4As4 single crystals. The J c can be respectively enlarged more than 3 and 50 times in H parallel to c-axis () and ab-plane () at temperature of 5 K and high magnetic fields of 8 T when the d is reduced from 88 to 2.0 . It is surprising to find that, accompanied by the

We investigate material properties in Mo x Si1−x thin films with the goal of optimization for single-photon detection from UV to mid-IR wavelengths. Saturated internal detection efficiency appears to be related to film structure for this material. We demonstrate nanometer-wide meander devices with saturated internal efficiency at 370 nm wavelength and 3.4 K operation temperature. By reducing the film

Ultra-fast growth (up to 100 nm s−1) of high temperature superconducting film was demonstrated by using an advanced pulsed laser deposition technique. Highly textured EuBa2Cu3O7−δ (EuBCO) film with 8 mol.% of BaHfO3 (BHO) was deposited on the IBAD-based Hastelloy substrates. Structure characterizations reveal formation of high density of BHO nanocolumns with diameter of ∼5 nm in the film, which is

In this paper, we investigate the manipulation of vortex arrays of magnetic flux by using dynamic heat sources in the superconducting strip. The time-dependent Ginzburg–Landau (TDGL) equations and the heat diffusion equation are numerically solved to study the effect of the dynamic heat sources and the vortex dynamics of the sample. Three distinct velocity ranges were shown to occur, depending on the

In order to confirm the superconductivity observed in hexagonal ϵ-NbN reported recently, we have deposited NbN film on (0001) 4H-SiC substrate, with good lattice match, intentionally to grow hexagonal NbN phase. The detailed structural analysis show that the deposited films are (111)-orientated δ-NbN phase with dense rotational (60) twins. Double diffraction effect in selected area electron diffraction

We report on the development of magnetic background field-tolerant superconducting quantum interference filter (SQIF) based on low-capacitance sub-micrometer sized cross-type Josephson junctions either as current sensing amplifiers—even on chip—for advanced superconducting quantum interference device (SQUID) readout circuits or as magnetic field sensor in flux transformer configuration especially for

Among various high-temperature superconducting materials, Bi2Sr2CaCu2O8+x (Bi-2212) is considered as one of the most promising candidates to fabricate superconductors for magnetic confinement fusion reactors. Considering that the superconductors will be subject to irradiation in nuclear reactors, the effects of gamma-ray irradiation on the superconducting properties of Bi-2212 wires is studied in the

The superheating field of the Meissner state is thought to determine the theoretical field-limit of superconducting accelerator cavities. We investigate of semi-infinite superconductors and layered structures in the diffusive limit using the well-established quasiclassical Green’s function formalism of the BCS theory. The coupled Maxwell–Usadel equations are self-consistently solved to obtain the spatial

The overall purpose of this work is to develop a reliable and low-cost technique for fabrication of coated conductors (CCs) on the flexible substrates, and to understand the effects of oriented growth and microstructure on the superconducting performance of CCs in-depth. The investigations of gradient La2−x Gd x Zr2O7 buffer architecture and YBa2Cu3O7−δ (YBCO) film on Ni-5at%W rolling-assisted biaxially

Superconducting electric propulsion systems, characterized by high power densities and efficiencies, provide a possibility to zero carbon emission for future aviation. Stacks of high temperature superconducting (HTS) coated conductors (CCs) have become an alternative for high field magnets applied to superconducting machines, given their excellent field trapping ability and thermal stability. High-frequency

122 type iron-based superconductors (IBSs) are potential for high-field applications, and the fabrication of high-performance IBS wires and tapes is essential. By using the powder-in-tube method, transport critical current density (J c) of hot-pressed (HP) silver-sheathed Ba1−x K x Fe2As2 (Ba-122) tapes have reached 1.5 105 A cm−2 at 4.2 K and 10 T. However, the J c of flat-rolled (FR) tapes is 6.2

The magnetization and resistivity measurements have been done to investigate the superconducting fluctuations effect above the superconducting transition temperature (T c) in (Li1−x Fe x )OHFeSe single crystal. These measurements were performed with applying the external magnetic fields in the ab plane of (Li1−x Fe x )OHFeSe single crystal. By analyzing the diamagnetism response and excess conductivity

We have been developing readout interfaces for superconducting nanowire single-photon detectors (SSPDs) using adiabatic quantum-flux-parametron (AQFP) logic. AQFP circuits operate with low power consumption, low bias currents, and high sensitivity, and thus are suitable as readout interfaces for large SSPD arrays. In this study, we develop a high-sensitivity AQFP interface, consisting of a current

Superconducting devices have been widely studied over these years. Their application can be found in cables for electric power transmission, energy storage systems, magnetic levitation, electric machines, and fault current limiters. The literature presents some formulations to model the superconductors’ behavior using the finite element method (FEM), such as the H, the AV, and the T formulations, among

The many advantages of cryogenically cooled single-flux quantum (SFQ) circuits imply that the high speed and low voltage output signals must be amplified and interfaced with standard electronics. State-of-the-art low-noise and wide-band amplifiers are required to interface with room temperature electronics. One solution is to place preamplifiers at the cryogenic stage, which requires specific semiconductor

We present a simple liquid-assisted processing (LAP) method, to be used in situ during pulsed laser deposition growth to give both rapid growth rates (50 Hz deposition leading to >250 nm min−1 with a single plume) and strong pinning (improved 5–10 at 30 K and below, over plain standard YBCO films grown at similar rates). Achieving these two important features simultaneously has been a serious bottleneck

Seven MgB2 bulk superconductors with good superconductivity and crystallinity were prepared under the pressure of 50 MPa at 950 C and different sintering durations (15 ∼ 240 min) by spark plasma sintering (SPS), with the onset critical temperature (T c,onset) around 37.5 K. The superconducting properties and microstructure measured from the facets perpendicular (PeF) and parallel (PaF) to the compression