scholarly journals High-Frequency Nonlinear Transport and Photogalvanic Effects in 2D Topological Insulators

2019 ◽  
Vol 531 (6) ◽  
pp. 1800418 ◽  
Author(s):  
Mikhail V. Durnev ◽  
Sergey A. Tarasenko
Keyword(s):  
High Frequency ◽  
Topological Insulators ◽  
Nonlinear Transport

scholarly journals Brillouin-Wigner theory for high-frequency expansion in periodically driven systems: Application to Floquet topological insulators

2016 ◽  
Vol 93 (14) ◽  
Author(s):  
Takahiro Mikami ◽  
Sota Kitamura ◽  
Kenji Yasuda ◽  
Naoto Tsuji ◽  
Takashi Oka ◽  
...  
Keyword(s):  
High Frequency ◽  
Topological Insulators ◽  
Driven Systems ◽  
Periodically Driven

NONLINEAR TRANSPORT OF ELECTRONS UNDER A STRONG HIGH FREQUENCY ELECTRIC FIELD IN SEMICONDUCTORS

1992 ◽  
Vol 06 (07) ◽  
pp. 1007-1036 ◽  
Author(s):  
W. Cai ◽  
M. Lax
Keyword(s):  
Electric Field ◽  
High Frequency ◽  
Second Harmonic ◽  
Memory Function ◽  
Harmonic Component ◽  
Nonlinear Transport ◽  
Field Limit ◽  
High Frequency Electric Field ◽  
Dc Electric Field ◽  
Harmonic Components

The nonlinear transport of electrons in semiconductors is studied when a strong high frequency (HF) electric field is applied together with a direct current (dc) electric field. A set of equations is developed, from which the amplitude and phase of each harmonic component of the electron drift velocity and the electron temperature can be computed. In the weak HF field limit our approach reduces to the well-known memory function method. The DC conductivity decreases and definitely becomes negative with increase of the first and second harmonic components of the applied HF field. Comparison is made with experiment.

scholarly journals Effect of high-frequency pumping on thin-film topological insulators

2018 ◽  
Vol 1092 ◽  
pp. 012114
Author(s):  
A A Pervishko ◽  
D Yudin ◽  
I A Shelykh
Keyword(s):  
Thin Film ◽  
High Frequency ◽  
Topological Insulators

scholarly journals Room-Temperature High-Frequency Transport of Dirac Fermions in Epitaxially GrownSb2Te3- andBi2Te3-Based Topological Insulators

2014 ◽  
Vol 113 (9) ◽  
Author(s):  
P. Olbrich ◽  
L. E. Golub ◽  
T. Herrmann ◽  
S. N. Danilov ◽  
H. Plank ◽  
...  
Keyword(s):  
High Frequency ◽  
Topological Insulators ◽  
Room Temperature ◽  
Dirac Fermions

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.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

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