scholarly journals Effects of Nonmagnetic Impurities and Subgap States on the Kinetic Inductance, Complex Conductivity, Quality Factor, and Depairing Current Density

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Takayuki Kubo
Keyword(s):  
Quality Factor ◽  
Current Density ◽  
Complex Conductivity ◽  
Kinetic Inductance ◽  
Nonmagnetic Impurities

scholarly journals Design evaluation of microwave transmission properties of YBa2Cu3O7 -based kinetic inductance detectors

2021 ◽  
Author(s):  
Seiichiro Ariyoshi ◽  
Hikaru Mikami ◽  
Atsushi Ebata ◽  
Satoshi Ohnishi ◽  
Takeshi Hizawa ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Quality Factor ◽  
Terahertz Wave ◽  
Kinetic Inductance Detectors ◽  
Kinetic Inductance ◽  
Network Analyzer ◽  
Microwave Resonance ◽  
Transmission Properties ◽  
Wave Antenna ◽  
Microwave Transmission

Abstract We designed, fabricated, and characterized microwave transmission properties with rewound strip structures for YBa2Cu3O7 (YBCO)-based kinetic inductance detectors (KIDs). The superconducting rewound strip serves as a microwave resonator and as a broadband terahertz-wave antenna. To predict the microwave resonance characteristics before fabrication, the line-width (w) and space (s) dependence of the spiral resonators were analyzed using an electromagnetic simulator; the resonance frequency increased, and the quality factor decreased with increasing w and s from 10 to 40 μm. YBCO-based KID arrays with different w (10 and 40 μm) were fabricated on 10 mm-square MgO substrates, cooled to 3 K using a 4He refrigerator, and evaluated using a vector network analyzer to verify the result of the simulation experimentally. The measured resonance frequency ratio of 1.11 times (5.04 → 5.59 GHz) agreed with the simulated ones of 1.10 times (4.84 → 5.33 GHz) between w = 10 and 40 μm. The other resonance characteristics, such as transmission coefficient and quality factor, have a similar w dependence with the simulation.

scholarly journals Optical tuning and ultrafast dynamics of high-temperature superconducting terahertz metamaterials

Nanophotonics ◽  
2012 ◽  
Vol 1 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Ranjan Singh ◽  
Jie Xiong ◽  
Abul K. Azad ◽  
Hao Yang ◽  
Stuart A. Trugman ◽  
...  
Keyword(s):  
High Temperature ◽  
Near Infrared ◽  
Frequency Tuning ◽  
Theoretical Calculations ◽  
Superconducting Films ◽  
Femtosecond Laser Pulses ◽  
Complex Conductivity ◽  
Kinetic Inductance ◽  
Resonance Strength ◽  
High Temperature Superconducting

AbstractThrough the integration of semiconductors or complex oxides into metal resonators, tunable metamaterials have been achieved by a change of environment using an external stimulus. Metals provide high conductivity to realize a strong resonant response in metamaterials; however, they contribute very little to the tunability. The complex conductivity in high-temperature superconducting films is highly sensitive to external perturbations, which provides new opportunities in achieving tunable metamaterials resulting directly from the resonant elements. Additionally, superconducting metamaterials are expected to enable strong nonlinear response and quantum effects, particularly when Josephson junctions are integrated into the metamaterial resonant elements. Here we demonstrate ultrafast dynamical tuning of resonance in the terahertz (THz) frequency range in YBa2Cu3O7-δ (YBCO) split-ring resonator (SRR) arrays excited by near infrared femtosecond laser pulses. The photoexcitation breaks the superconducting Cooper pairs to create quasiparticles. This dramatically modifies the imaginary part of the complex conductivity and consequently the metamaterial resonance on an ultrafast timescale, although the real conductivity does not change significantly. We observed resonance switching accompanied by substantial frequency tuning as a function of photoexcitation fluence, which also strongly depends on the nanoscale thickness of the superconducting films. All of our experimental results agree with calculations using an analytical model, which takes into account the contributions of the complex conductivity of the YBCO films to SRR resistance and kinetic inductance. The theoretical calculations reveal that the increasing SRR resistance upon increasing photoexcitation fluence is responsible for the reduction of resonance strength, and changes in both the resistance and kinetic inductance cause the resonance frequency shifts.

scholarly journals High quality factor platinum silicide microwave kinetic inductance detectors

2016 ◽  
Vol 109 (15) ◽  
pp. 151102 ◽  
Author(s):  
P. Szypryt ◽  
B. A. Mazin ◽  
G. Ulbricht ◽  
B. Bumble ◽  
S. R. Meeker ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Quality Factor ◽  
Kinetic Inductance Detectors ◽  
Kinetic Inductance ◽  
High Quality ◽  
Microwave Kinetic Inductance Detectors ◽  
Platinum Silicide

scholarly journals High quality factor manganese-doped aluminum lumped-element kinetic inductance detectors sensitive to frequencies below 100 GHz

2017 ◽  
Vol 110 (22) ◽  
pp. 222601 ◽  
Author(s):  
G. Jones ◽  
B. R. Johnson ◽  
M. H. Abitbol ◽  
P. A. R. Ade ◽  
S. Bryan ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Quality Factor ◽  
Kinetic Inductance Detectors ◽  
Kinetic Inductance ◽  
High Quality ◽  
Lumped Element

Activated Prominences; Mechanisms for Activation and Eruption

1979 ◽  
Vol 44 ◽  
pp. 307-313
Author(s):  
D.S. Spicer
Keyword(s):  
Pressure Gradient ◽  
Density Gradient ◽  
Current Density ◽  
Convective Instability ◽  
Tearing Mode ◽  
Magnetic Shear ◽  
Long Wavelength ◽  
Ideal Mhd ◽  
Gradient Change ◽  
Accelerated Particles

A possible relationship between the hot prominence transition sheath, increased internal turbulent and/or helical motion prior to prominence eruption and the prominence eruption (“disparition brusque”) is discussed. The associated darkening of the filament or brightening of the prominence is interpreted as a change in the prominence’s internal pressure gradient which, if of the correct sign, can lead to short wavelength turbulent convection within the prominence. Associated with such a pressure gradient change may be the alteration of the current density gradient within the prominence. Such a change in the current density gradient may also be due to the relative motion of the neighbouring plages thereby increasing the magnetic shear within the prominence, i.e., steepening the current density gradient. Depending on the magnitude of the current density gradient, i.e., magnetic shear, disruption of the prominence can occur by either a long wavelength ideal MHD helical (“kink”) convective instability and/or a long wavelength resistive helical (“kink”) convective instability (tearing mode). The long wavelength ideal MHD helical instability will lead to helical rotation and thus unwinding due to diamagnetic effects and plasma ejections due to convection. The long wavelength resistive helical instability will lead to both unwinding and plasma ejections, but also to accelerated plasma flow, long wavelength magnetic field filamentation, accelerated particles and long wavelength heating internal to the prominence.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

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