Analysis of effective coupling strength in high‐frequency SQUIDs

1995 ◽  
Vol 78 (10) ◽  
pp. 6276-6282 ◽  
Author(s):  
M. Gottschlich ◽  
E. Sodtke ◽  
Y. Zhang ◽  
A. M. Portis
Keyword(s):  
Coupling Strength ◽  
High Frequency ◽  
Effective Coupling

scholarly journals On the Effective Coupling Strength in the Static Pion Theory

1957 ◽  
Vol 18 (1) ◽  
pp. 89-91
Author(s):  
Tetsuro Kobayashi ◽  
Jun'ichi Osada ◽  
Smio Tani
Keyword(s):  
Coupling Strength ◽  
Effective Coupling

scholarly journals Unconventional Superconductivity in Samarium Nitride

2021 ◽  
Author(s):  
◽  
William Doonan
Keyword(s):  
Fermi Level ◽  
Coupling Strength ◽  
Band System ◽  
Pair Potential ◽  
Effective Model ◽  
Unconventional Superconductivity ◽  
Effective Coupling ◽  
Triplet Pairing ◽  
Nitrogen Ion ◽  
Special Case

<p>We have studied the nature of unconventional superconductivity in the rare-earth nitride (REN) samarium nitride (SmN) for the purposes of providing a deeper understanding of the mechanisms that lead to such a phenomenon in an already extremely interesting material. An approximate low energy model has been introduced for SmN based on previous bandstructure calculation and recent experimental results. This consists of the non-dispersive 4f band associated with the samarium ion crossing through the dispersive 5d band associated with the nitrogen ion. Due to large spin polarisation in the bandstructure we need only consider the majority-spin 5d and 4f bands which lead to an essentially spinless two band system. Starting from this two band system, we apply the k dot p method to it in order to create an effective model for the system. This effective model for the material acts as the platform from which we study the possible triplet superconducting pairing. Basing our pairing on the electron-phonon interaction we have postulated the existence of triplet pairing in the 5d band, from which we have successfully characterised the pair potential in this system through the self-consistency equation. The pair potential Delta_d could be solved analytically in a special case where the Fermi level was equal to the 4f band. In this case we find that above a threshold effective coupling strength the superconducting state is established and analytically known. In contrast to this result for the more general case where the Fermi level is different to the 4f band we numerically recover a solution that was exponential in the effective coupling strength which is similar to the pairing as we expect from the single band case. Analytic solutions in this case were not able to be found, however, we know that from our numerical investigations there will exist a solution for any effective coupling strength, contrasting with the special case where the pairing amplitude can disappear below a certain threshold. In conjunction to these results we also examined the situation where the 5d and 4f bands have hybridised together in order to search for unique pairing that may be resistant to disorder. By keeping the triplet pairing only in the 5d band, this translates to hybrid pairing between electrons in the two hybridised bands. Results from the hybridised bands system show a new singlet-like pairing Delta_S which is even in k and singlet in the hybridised band indices. Preliminary numerical results suggest that this pairing indeed exists and occurs only near the avoided crossing of the hybridised bands. The existence of such a pairing, originating from triplet pairing, has exciting implications for the robustness of the superconductivity in the presence of disorder and/or impurities.</p>

scholarly journals Evolution of high-frequency Raman modes and their doping dependence in twisted bilayer MoS2

Nanoscale ◽  
2020 ◽  
Vol 12 (33) ◽  
pp. 17272-17280 ◽  
Author(s):  
Rahul Debnath ◽  
Indrajit Maity ◽  
Rabindra Biswas ◽  
Varun Raghunathan ◽  
Manish Jain ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Coupling Strength ◽  
First Principles ◽  
High Frequency ◽  
Twist Angle ◽  
Interlayer Coupling ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Raman Modes ◽  
Systematic Evolution

Here, we demonstrate the systematic evolution of the interlayer coupling and electron-phonon coupling strength with twist angle in bilayer MoS2 using a combination of Raman spectroscopy and a combination of classical and first-principles based simulations.

scholarly journals Effective coupling of rapid freeze-quench to high-frequency electron paramagnetic resonance

PLoS ONE ◽  
2020 ◽  
Vol 15 (5) ◽  
pp. e0232555
Author(s):  
E. Gabriele Panarelli ◽  
Harmen van der Meer ◽  
Peter Gast ◽  
Edgar J J. Groenen
Keyword(s):  
Electron Paramagnetic Resonance ◽  
High Frequency ◽  
Effective Coupling ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Effect of coupling strength on the intermodulation distortion in DFB laser

1996 ◽  
Vol 74 (S1) ◽  
pp. 5-8 ◽  
Author(s):  
Hanan Anis ◽  
J. Goodwin ◽  
T. Makino ◽  
J. M. Xu
Keyword(s):  
Coupling Strength ◽  
High Frequency ◽  
Relaxation Oscillation ◽  
Low Frequency ◽  
Intermodulation Distortion ◽  
Frequency Regime ◽  
Dfb Laser

In this work the effect of increasing the coupling strength on the intermodulation distortion is investigated. It is shown that only if other effects such as the change in the relaxation oscillation are absent, higher coupling strength leads to a higher intermodulation distortion. Otherwise, the dependence of distortion on the coupling strength is not monotonic and exhibits trends in the mid- and high-frequency regimes that are very different from that in the low-frequency regime.

scholarly journals Unconventional Superconductivity in Samarium Nitride

2021 ◽  
Author(s):  
◽  
William Doonan
Keyword(s):  
Fermi Level ◽  
Coupling Strength ◽  
Band System ◽  
Pair Potential ◽  
Effective Model ◽  
Unconventional Superconductivity ◽  
Effective Coupling ◽  
Triplet Pairing ◽  
Nitrogen Ion ◽  
Special Case

<p>We have studied the nature of unconventional superconductivity in the rare-earth nitride (REN) samarium nitride (SmN) for the purposes of providing a deeper understanding of the mechanisms that lead to such a phenomenon in an already extremely interesting material. An approximate low energy model has been introduced for SmN based on previous bandstructure calculation and recent experimental results. This consists of the non-dispersive 4f band associated with the samarium ion crossing through the dispersive 5d band associated with the nitrogen ion. Due to large spin polarisation in the bandstructure we need only consider the majority-spin 5d and 4f bands which lead to an essentially spinless two band system. Starting from this two band system, we apply the k dot p method to it in order to create an effective model for the system. This effective model for the material acts as the platform from which we study the possible triplet superconducting pairing. Basing our pairing on the electron-phonon interaction we have postulated the existence of triplet pairing in the 5d band, from which we have successfully characterised the pair potential in this system through the self-consistency equation. The pair potential Delta_d could be solved analytically in a special case where the Fermi level was equal to the 4f band. In this case we find that above a threshold effective coupling strength the superconducting state is established and analytically known. In contrast to this result for the more general case where the Fermi level is different to the 4f band we numerically recover a solution that was exponential in the effective coupling strength which is similar to the pairing as we expect from the single band case. Analytic solutions in this case were not able to be found, however, we know that from our numerical investigations there will exist a solution for any effective coupling strength, contrasting with the special case where the pairing amplitude can disappear below a certain threshold. In conjunction to these results we also examined the situation where the 5d and 4f bands have hybridised together in order to search for unique pairing that may be resistant to disorder. By keeping the triplet pairing only in the 5d band, this translates to hybrid pairing between electrons in the two hybridised bands. Results from the hybridised bands system show a new singlet-like pairing Delta_S which is even in k and singlet in the hybridised band indices. Preliminary numerical results suggest that this pairing indeed exists and occurs only near the avoided crossing of the hybridised bands. The existence of such a pairing, originating from triplet pairing, has exciting implications for the robustness of the superconductivity in the presence of disorder and/or impurities.</p>

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

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