A5091855317- Physics of Superconductivity and Magnetism
- Superconductivity in MgB2 and Alloys
- Acoustic Wave Resonator Technologies
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Advanced Electrical Measurement Techniques
- Iron-based superconductors research
- Rare-earth and actinide compounds
- Magneto-Optical Properties and Applications
- Microwave Engineering and Waveguides
- Superconducting and THz Device Technology
- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Terahertz technology and applications
- Nuclear materials and radiation effects
- Gyrotron and Vacuum Electronics Research
- Advanced Antenna and Metasurface Technologies
- Advanced ceramic materials synthesis
- Microwave Dielectric Ceramics Synthesis
- Luminescence Properties of Advanced Materials
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Ergonomics and Musculoskeletal Disorders
Shanghai Academy of Spaceflight Technology
2024
Sichuan Normal University
2024
Nankai University
2004-2014
Forschungszentrum Jülich
2006
University of Kansas
1998-2003
Vrije Universiteit Amsterdam
1997
The current density ${j}_{s}$ and relaxation rate $Q$ have been measured on a ring shaped ${\mathrm{Tl}}_{2}{\mathrm{Ba}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8}$ film between 4.2 K the irreversibility temperature in magnetic fields up to 7 T. field dependent exponent $\ensuremath{\mu}({T,B}_{e})$ used parametrize activation energy $U$ form $U({j}_{s}{,T,B}_{e})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({U}_{c}/\ensuremath{\mu})[({j}_{c}{/j}_{s}{)}^{\ensuremath{\mu}}\ensuremath{-}1]$...
High quality superconducting HgBa2CaCu2Ox (Hg-1212) thin films have been reproducibly fabricated using cation-exchange method. The pure Hg-1212 phase and smooth surface morphology. transition temperatures of these are in the range 120–124 K. critical current density Jc is up to 3.2×106 A/cm2 at 77 K drops only by a factor 2 100 self field. At 110 K, 7.8×105 has obtained. X-ray diffraction pole figures show that epitaxially grown on LaAlO3(001) substrates, which consistent with χmin 19%...
A cation-exchange process has been developed for growth of high-quality epitaxial thin films highly volatile mercury-based high-temperature superconductors. By selecting precursor matrices TlyBa2CaCu2Ox (y=1,2) and annealing them in Hg vapor, c-axis-oriented HgBa2CaCu2O6+δ with superior quality were formed through Tl Hg-cation exchange. At 110 K, these can carry supercurrent density close to 1 MA/cm2 which is nearly an order magnitude higher than the best reported previously. This technique...
The authors have explored the coupling mechanism of a millimeter wave radiation to bicrystal Josephson junction arrays embedded in hemispherical Fabry-Pérot resonator. found that their high-temperature superconductor array can be modeled as thin film grid polarizer. In agreement with this model, strong dependence junctions on polarization electric filed resonator was observed. achieved maximum voltage 28mV for an 182 at temperature 75K and frequency 74.4GHz.
This work aims to investigate the influence of Ca[Formula: see text] doping on infrared emission properties DyTa 3 O 9 ceramics. is considered a promising high-temperature thermal protection material due its low conductivity and good stability. However, there currently no research radiation performance such materials. We synthesized ceramics with different concentrations using solid-phase reaction method systematically investigated effect concentration emissivity When doped into lattice,...
We proposed a novel approach to self-radiation of Josephson junction arrays. Bicrystal arrays fabricated on bicrystal substrate were integrated with half-wavelength dipole array and embedded in Fabry–Perot resonator. Considered as dielectric resonator, the could be stimulated resonate an appropriate mode at same frequency which realized coupling between junctions well microwave structures by means resonant interaction resonators. Both simulations experiments performed. A YBCO 166 was...
By analyzing I-V characteristics (E-j curves), which were experimentally determined on Tl2Ba2CaCu2O8 thin films in magnetic fields Be varying from 0 T to 5 T, we find that the transition of linear resistivity ρlin = [E/j]j → signaling superconductivity exhibits different criticalities for fields. Starting with a Berezinskii-Kosterlitz-Thouless at TBKT 103.7 K one induces crossover quasi-2D or 3D vortex-glass finite Tg below few kOe, and finally "true" 2D higher We argue this field-induced is...
We report on a study of the in-plane infrared response ${\mathrm{Tl}}_{2}{\mathrm{Ba}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$ film with ${T}_{c}=108\mathrm{K}.$ The fingerprint evidence for strong electron-boson coupling has been observed. raw reflectance below ${T}_{c}$ exhibits knee structure at around $650{\mathrm{cm}}^{\ensuremath{-}1}$ and ratio reflectances above displays pronounced minimum $1000{\mathrm{cm}}^{\ensuremath{-}1}.$ In particular, features appear...
By measuring the magnetization hysteresis loops and remanent relaxation for an epitaxial ${\mathrm{Tl}}_{2}$${\mathrm{Ba}}_{2}$${\mathrm{CaCu}}_{2}$${\mathrm{O}}_{8}$ thin film, we determined temperature dependence of experimental critical current density j(T) normalized rate S(T) at ${\mathit{B}}_{\mathit{e}}$=0.4 T. It is shown that data can be well fitted to single vortex creep model with only one fitting parameter in each process. The were then used as input generalized inversion scheme...
Nonlinear inductance of intrinsic Josephson junction arrays in Tl-2212 thin films has been investigated. Misaligned were fabricated on 20deg vicinal substrates and then patterned into long bridges by standard photolithography wet chemical etching. Each bridge forms a large array junctions. We have measured the zero-DC-voltage state at 77 K show that its dependence critical current is good agreement with theory. Also, we numerically studied nonlinearity present distortion factor bias AC...
The irreversibility lines of epitaxial thin films ${\mathrm{HgBa}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{6+\ensuremath{\delta}}$ and ${\mathrm{TlBa}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}},$ whether deduced from field-induced magnetoresistive broadening or onset nonhysteretic magnetization, were found to coincide when plotted against reduced temperature, showing the same exponential-decay temperature behavior for ${T/T}_{c}<0.8$ power-law ${T/T}_{c}>0.8$...
The dynamics of capacitively coupled intrinsic Josephson junction arrays with a McCumber parameter βc<1 driven by dc current are investigated using numerical simulations. For the first time, spatiotemporal chaotic behaviors found. Analysis individual junctions shows that chaos is caused strong diffusive coupling between in array. regions different parameters also presented, from which conditions for deduced. properties array shunted an LCR series resonance circuit investigated. results show...
We report on the investigation of coupling mechanism a resonant millimeter wave electromagnetic field with bicrystal Josephson junction arrays embedded in hemispherical Fabry-Perot resonator. have found that our high-temperature superconductor array can be modeled as thin film grid polarizer. In agreement this model strong dependence junctions polarization electric resonator was measured. Numerical simulations confirm model. According to model, dimension and interval grids are optimized by...
The availability of high-quality epitaxial thin films HgBa2CaCu2O6+δ (Hg-1212) and TlBa2CaCu2O7 (Tl-1212) with high critical current densities (Jc) has made it possible to examine compare the Jc these species. Results reveal that 1212 species have very similar temperature behavior at low fields, strongly suggesting 30 K shift in (Tc) induced by exchange Hg Tl structure is due largely a change charge carrier density and/or electronic band structure.
By measuring the temperature dependence of magnetoresistivity Tl2Ba2CaCu2O8 thin films, two superconducting transitions were observed for field orientations in H⊥ab- and H∥ab-planes. The transition at high (Tch) corresponds to a steep peak derivative effective activation energy shifts very moderately with increasing magnetic field. is good agreement value upper critical derived from fluctuation theory. Meanwhile, low (Tcl) was associated Josephson coupling strong intrinsic pinning...