Novel superconducting states in nanoscale superconductors

2017 ◽  
Author(s):  
A. Kanda ◽  
Y. Ootuka ◽  
K. Kadowaki ◽  
F.M. Peeters
Keyword(s):  
Tunnel Junction ◽  
Recent Progress ◽  
Superconducting Films ◽  
Direct Visualization ◽  
Indirect Methods ◽  
Theoretical Methods ◽  
One Dimensional ◽  
Vortex States ◽  
Theoretical Predictions ◽  
Mesoscopic Superconductors

This article describes novel superconducting states in nanoscale superconductors. It first considers characteristic lengths in superconductors and vortices in mesoscopic superconductors before discussing trends in superconductivity research, which is closely related to recent progress in nanotechnology. It then explains the theoretical methods used for the study of mesoscopic superconducting states, along with theoretical predictions of vortex states in thin mesoscopic superconducting films. It also looks at experimental techniques used for the detection of vortices, including direct visualization of the vortex positions and indirect methods such as the multiple-small-tunnel-junction method, and experimental detection of mesoscopic vortex states in disks and squares. Finally, it evaluates one-dimensional vortex in mesoscopic rings.

Theoretical and numerical structure of unstable detonations

1995 ◽  
Vol 350 (1692) ◽  
pp. 29-68 ◽  
Keyword(s):  
Numerical Simulations ◽  
Numerical Method ◽  
Recent Progress ◽  
Simplified Models ◽  
One Dimensional ◽  
Numerical Predictions ◽  
Theoretical Predictions ◽  
Linear And Nonlinear ◽  
Physical Phenomena ◽  
Insight Into

In this review, we emphasize the recent progress achieved in understanding the behaviour of unstable detonations through the interaction of theoretical, asymp­ totic, and numerical ideas. Theoretical predictions and numerical simulations for unstable one-dimensional detonations are described in detail as an important testing ground for the more complex ideas and phenomena that occur in several space dimensions. The linear and nonlinear theories for unstable detonations are generalized to several space dimensions. A new dedicated numerical method leads to better insight into the physical phenomena of unstable detonations, such as the nature of the turbulence generated in the wake of the front. Simplified models derived through asymptotics and comparisons between theoretical and numerical predictions are stressed throughout this paper.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

scholarly journals Quantitative Experimental and Theoretical Investigations on the Interaction of Shock Waves with Magnetic Fields

1969 ◽  
Vol 24 (10) ◽  
pp. 1449-1457
Author(s):  
H. Klingenberg ◽  
F. Sardei ◽  
W. Zimmermann
Keyword(s):  
Magnetic Fields ◽  
Shock Waves ◽  
Physical Model ◽  
Spectroscopic Method ◽  
Experimental Results ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Theoretical Investigations ◽  
Theoretical Predictions ◽  
Interaction Of Shock Waves

Abstract In continuation of the work on interaction between shock waves and magnetic fields 1,2 the experiments reported here measured the atomic and electron densities in the interaction region by means of an interferometric and a spectroscopic method. The transient atomic density was also calculated using a one-dimensional theory based on the work of Johnson3 , but modified to give an improved physical model. The experimental results were compared with the theoretical predictions.

scholarly journals Chain paradoxes

2015 ◽  
Vol 471 (2173) ◽  
pp. 20140657 ◽  
Author(s):  
Epifanio G. Virga
Keyword(s):  
Present Theory ◽  
One Dimensional ◽  
Dissipative Dynamics ◽  
Theoretical Predictions

For nearly two centuries, the dynamics of chains have offered examples of paradoxical theoretical predictions. Here, we propose a theory for the dissipative dynamics of one-dimensional continua with singularities which provides a unified treatment for chain problems that have suffered from paradoxical solutions. These problems are duly solved within the present theory and their paradoxes removed—we hope.

Recent Progress in III-Nitride Tunnel Junction-Based Optoelectronics

2019 ◽  
Vol 28 (01n02) ◽  
pp. 1940012
Author(s):  
Zane Jamal-Eddine ◽  
Yuewei Zhang ◽  
Siddharth Rajan
Keyword(s):  
Tunnel Junction ◽  
Recent Progress ◽  
Tunnel Junctions ◽  
Optoelectronic Devices ◽  
Material System ◽  
Novel Device ◽  
Unique Material ◽  
Material Systems ◽  
Device Applications ◽  
Commercial Device

Tunnel junctions have garnered much interest from the III-Nitride optoelectronic research community within recent years. Tunnel junctions have seen applications in several material systems with relatively narrow bandgaps as compared to the III-Nitrides. Although they were initially dismissed as ineffective for commercial device applications due to high voltage penalty and on resistance owed to the wide bandgap nature of the III-Nitride material systems, recent development in the field has warranted further study of such tunnel junction enabled devices. They are of particular interest for applications in III-Nitride optoelectronic devices in which they can be used to enable novel device designs which could potentially address some of the most challenging physical obstacles presented with this unique material system. In this work we review the recent progress made on the study of III-Nitride tunnel junction-based optoelectronic devices and the challenges which are still faced in the field of study today.

UNBOUNDED SETS OF ATTRACTION

2000 ◽  
Vol 10 (06) ◽  
pp. 1437-1469 ◽  
Author(s):  
GIAN-ITALO BISCHI ◽  
CHRISTIAN MIRA ◽  
LAURA GARDINI
Keyword(s):  
Functional Equation ◽  
Two Dimensional ◽  
Elementary Functions ◽  
Theoretical Methods ◽  
One Dimensional ◽  
Zero Measure ◽  
Analytical Expressions

In this paper we show that unbounded chaotic trajectories are easily observed in the iteration of maps which are not defined everywhere, due to the presence of a denominator which vanishes in a zero-measure set. Through simple examples, obtained by the iteration of one-dimensional and two-dimensional maps with denominator, the basic mechanisms which are at the basis of the existence of unbounded chaotic trajectories are explained. Moreover, new kinds of contact bifurcations, which mark the transition from bounded to unbounded sets of attraction, are studied both through the examples and by general theoretical methods. Some of the maps studied in this paper have been obtained by a method based on the Schröoder functional equation, which allows one to write closed analytical expressions of the unbounded chaotic trajectories, in terms of elementary functions.

scholarly journals Fabrication of Beltlike Fibers by Electrospinning

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1087 ◽  
Author(s):  
Yan-Qing Liu ◽  
Chun-Hui He ◽  
Xiao-Xia Li ◽  
Ji-Huan He
Keyword(s):  
Surface Tension ◽  
Polyethylene Glycol ◽  
Theoretical Analysis ◽  
Minimal Surface ◽  
Crystallite Size ◽  
Zro2 Nanoparticles ◽  
One Dimensional ◽  
Theoretical Predictions ◽  
Spinning Process ◽  
Moving Jet

Electrospinning is always used to fabricate one-dimensional nanofibers. Cylindrical fibers are formed during the spinning process due to the minimal-surface principle. However, when the moving jet has high rigidity, which can counteract the surface tension for a minimal surface, beltlike fibers can be obtained. Using the Hall–Petch effect, the rigidity of the moving jet can be greatly enhanced by adding nanoparticles. Polyethylene glycol with a nanometric crystallite size of 4 nm and ZrO2 nanoparticles are used as additives in the experiment, a theoretical analysis is carried out, and the theoretical predictions are verified experimentally.

Impact and Bandgap Characteristics of Periodic Rods With Viscoelastic Inserts and Local Resonators

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Y. Alsaffar ◽  
O. Aldraihem ◽  
A. Baz
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Complex Modulus ◽  
Structural Response ◽  
Element Model ◽  
One Dimensional ◽  
Theoretical Predictions ◽  
Finite Element Package ◽  
Viscoelastic Composites ◽  
First Time

Abstract A comprehensive theoretical and experimental study is presented of the bandgap behavior of periodic viscoelastic material (VEM) composites subjected to impact loading. The composites under consideration consist of an assembly of aluminum sections integrated with periodic inserts which are arranged in one-dimensional configurations. The investigated inserts are manufactured either from VEM only or VEM with local resonators (LR). A finite element model (FEM) is developed to predict the dynamics of this class of VEM composites by integrating the dynamics of the solid aluminum sections with those of VEM using the Golla-Hughes-Mctavish (GHM) mini-oscillator approach. The integrated model enables, for the first time, the accurate predictions of the bandgap characteristics of periodic viscoelastic composites unlike previous studies where the viscoelastic damping is modeled using the complex modulus approach with storage modulus and loss factor are assumed constants and independent of the frequency or the unrealistic and physically inaccurate Kelvin–Voigt viscous-damping models. The predictions of the developed FEM are validated against the predictions of the commercial finite element package ansys. Furthermore, the FEM predictions are checked experimentally using prototypes of the VEM composites with VEM and VEM/LR inserts. Comparisons are also established against the behavior of plain aluminum rods in an attempt to demonstrate the effectiveness of the proposed class of composites in mitigation of the structural response under impact loading. Close agreements are demonstrated between the theoretical predictions and the obtained experimental results.

Vortex states in mesoscopic superconductors

2007 ◽  
Vol 71 (1) ◽  
pp. 6-9
Author(s):  
V. M. Vinokur ◽  
N. B. Kopnin ◽  
A. S. Mel’nikov ◽  
I. M. Nefedov ◽  
V. I. Pozdnyakova ◽  
...  
Keyword(s):  
Vortex States ◽  
Mesoscopic Superconductors
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