A5102864246- Physics of Superconductivity and Magnetism
- Acoustic Wave Resonator Technologies
- Microwave Engineering and Waveguides
- Advanced Antenna and Metasurface Technologies
- Iron-based superconductors research
- Superconducting and THz Device Technology
- Superconductivity in MgB2 and Alloys
- Advanced Frequency and Time Standards
- Antenna Design and Analysis
- Microwave Dielectric Ceramics Synthesis
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- Rare-earth and actinide compounds
- Heusler alloys: electronic and magnetic properties
- Advanced Electrical Measurement Techniques
- Particle accelerators and beam dynamics
- Metamaterials and Metasurfaces Applications
- Gyrotron and Vacuum Electronics Research
- Magnetic properties of thin films
- Cold Atom Physics and Bose-Einstein Condensates
- Microwave and Dielectric Measurement Techniques
- Photonic and Optical Devices
- Magneto-Optical Properties and Applications
- Terahertz technology and applications
- Shape Memory Alloy Transformations
Nankai University
2014-2025
Guangzhou College of Commerce
2024
Institute of Semiconductors
2013
Chinese Academy of Sciences
2013
University of Kansas
2008
University of Minnesota
2001-2005
Florida State University
2004
Perpendicularly magnetized τ-MnAl films have been epitaxied on GaAs (001) by molecular-beam epitaxy. Crystalline quality and magnetic properties of the samples were strongly dependent growth temperature. The highest coercivity 10.7 kOe, saturation magnetization 361.4 emu/cm3, perpendicular anisotropy constant 13.65 Merg/cm3, energy product 4.44 MGOe achieved. These tunable make MnAl valuable as excellent cost-effective alternative for not only high density recording storage spintronics...
Epitaxial Ni2MnGa and Ni2Mn1.2Ga0.8 thin films have been grown by molecular beam epitaxy on GaAs (001) substrates with Sc0.3Er0.7As interlayers. Structural characterization of as-grown confirms the epitaxially stabilized single crystal structure indicates that grow pseudomorphically in a tetragonal (a=b=5.65 Å, c=6.18 Å). The are ferromagnetic at room temperature coercivity ∼50 Oe, saturation magnetization ∼250 emu/cm3, weak in-plane magnetic anisotropy. Curie is found to be ∼340 K. However,...
We report the magnetotransport properties of epitaxial films full Heusler alloys Ni2MnGa, Ni2MnGe, and Ni2MnAl, grown by molecular beam epitaxy on (001) GaAs. The ferromagnetic (Ni2MnGa,Ni2MnGe) exhibit an anomalous temperature dependence resistivity a negative magnetoresistance peaking near Curie due to spin disorder scattering. Considering absolute values resistivity, high behavior upturn in below 20 K, we suggest that these rather than being conventional metals are fact strongly...
The ferromagnetic Heusler alloy Ni2MnIn has been grown on InAs (001) by molecular-beam epitaxy. In situ reflection high-energy electron diffraction, ex x-ray Rutherford backscattering spectrometry, and transmission microscopy indicate the high-quality epitaxial growth of with B2 crystal structure (001). Superconducting quantum interference device magnetometry shows that film is a Curie temperature ∼170 K.
Abstract The Josephson plasmon resonance (JPR) offers a valuable probe to investigate the superconductivity in layered cuprate superconductors. However, coupling between free space radiation and JPR high‐temperature superconductor (HTS) film remains challenging because excitation of demands c ‐axis oriented electric field. subwavelength resonators metamaterials can enhance localized field, which be utilized resolve this difficulty. Here, tunable terahertz (THz) metamaterial made from Tl 2 Ba...
This paper presents a compact C-band high-temperature superconducting (HTS) input module duplexer, which can be scaled to triplexer. The duplexer includes common node as the port, is an extensible and effective structure for integrating HTS multiplexer on single film. realized by open-loop microstrip line, resonates at frequency in guard band between two channels. In addition four-pole bandpass filters consisting of rectangular spiral line resonators are used output channels device. designed...
A novel scheme of a multi‐mode square ring resonator (MMSRR) is proposed in this study. To analyse the characteristics resonator, odd‐ and even‐mode based method used, which shows that basic type has five resonant modes three transmission zeros (TZs). The frequencies poles TZs can be changed by varying sizes lines flexibly. By properly parameters dual‐band bandpass filter (BPF) designed with central 1.78 3.04 GHz, respectively. explore further performance MMSRR, two single‐band BPFs...
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 ultrafast modulation of terahertz (THz) waves is essential for numerous applications, such as high-rate wireless communication, nonreciprocal transmission, and linear frequency conversion. However, high-speed THz devices are rare due to the lack materials that rapidly respond external stimuli. Here, we demonstrate a dynamic metasurface by introducing an ultrathin superconducting microbridge into metallic resonators form superconductor-metal hybrid structure. Exploiting susceptibility...
Heusler alloy Ni2MnIn thin films have been grown on InAs (001) by molecular beam epitaxy at growth temperatures ranging from 120 to 300 °C. For °C, transmission electron diffraction confirms the epitaxial of in B2 crystal structure with an relationship Ni2MnIn(001)⟨100⟩‖InAs(001)⟨100⟩. Magnetic measurements show that film is ferromagnetic a Curie temperature ∼170K. However, for °C followed postgrowth anneal 200 as high 330 K was obtained. The increase attributed formation partial L21...
High quality Tl2Ba2CaCu2O8 (Tl-2212) superconducting thin films were fabricated on 2 inch double-sided CeO2 buffered r-cut sapphire substrates. The metal cerium target was used as the sputtering source to deposit buffer layer by RF magnetron reactive technique, and inter-diffusion of chemical elements between substrate studied XPS depth profiling. crack-free Tl-2212 with dense crystal structure smooth morphology homogeneous over whole area film. XRD measurement confirmed purity phase texture...
Here, compact dual/tri‐band bandpass filters (BPFs) with tunable passbands are proposed. The multiband BPFs designed by combining a BPF passband and fixed using common external coupling line. former consists of dual‐mode resonator loaded varactors (DMVLR) the latter is composed quad‐mode (QMR). classical analysis method odd/even mode employed to analyse characteristics resonators. centre frequency (CF) can be easily tuned varying voltage imposed on varactors. A constant absolute bandwidth...
We implement a broadly tunable phase shifter for microwaves based on superconducting quantum interference devices (SQUIDs) and study it both experimentally theoretically. At different frequencies, unit transmission coefficient, |S21| = 1, can be theoretically achieved along curve where the shift is controllable by magnetic flux. The fabricated device consists of three equidistant SQUIDs interrupting line. model each SQUID embedded at positions line with two parameters, capacitance...
A high temperature superconducting (HTS) filter on double-sided Tl2Ba2Ca2Cu3O10 (Tl-2223) thin films is designed in this letter. High-quality Tl-2223 are prepared 10 × 0.5 mm3 LaAlO3 (001) substrate. The critical temperatures Tc of the 120 ± 1 K and current densities Jc 3–4 MA/cm2 at 77 for both sides. X-ray diffraction θ-2θ scans rotational ϕ-scans prove that strongly textured with c axis perpendicular to substrate surface. 3-pole band-pass then fabricated 4% relative bandwidth a center...
The microwave power handing capability Pc of the microstrip lines isomorphic '1212' pair is studied for superconductors TlBa2CaCu2O7 and HgBa2CaCu2O6+δ at ≥77 K. follows same temperature dependence a reduced scale (t = T/Tc). A comparison dc critical current density Jc radio-frequency one Jrf derived from reveals similar dependence, suggesting that depinning magnetic vortices, which dictated by structure, pays role in limiting proximity Tc.
We study the electromagnetic coupling mechanism of a Tl2Ba2CaCu2O8 (Tl-2212) thin film intrinsic Josephson junction to hemispherical Fabry—Perot resonator. An effective model analyze is put forward. The dielectric substrate used as resonator antenna and junction, superconducting feed line excite resonance mode inside antenna. To confirm this method, two samples with different dimensions shapes are fabricated tested under microwave irradiations. At same time, numerical simulations...