scholarly journals Relaxation of a single defect spin by the low-frequency gyrotropic mode of a magnetic vortex

2021 ◽  
Vol 130 (8) ◽  
pp. 083903
Author(s):  
J. Trimble ◽  
B. Gould ◽  
F. J. Heremans ◽  
S. S.-L. Zhang ◽  
D. D. Awschalom ◽  
...  
Keyword(s):  
Low Frequency ◽  
Magnetic Vortex ◽  
Single Defect

Bloch–Floquet bending waves in perforated thin plates

2007 ◽  
Vol 463 (2086) ◽  
pp. 2505-2518 ◽  
Author(s):  
A.B Movchan ◽  
N.V Movchan ◽  
R.C McPhedran
Keyword(s):  
Plane Waves ◽  
Low Frequency ◽  
Free Edge ◽  
Multipole Expansion ◽  
Thin Plates ◽  
Band Diagram ◽  
Single Defect ◽  
Bending Waves ◽  
Zero Radius ◽  
Square Array

This paper presents a mathematical model describing propagation of bending waves in a perforated thin plate. It is assumed that the holes are circular and form a doubly periodic square array. A spectral problem for the biharmonic operator is formulated in a unit cell containing a single defect, and its analytical solution is constructed using a multipole method. The overall system for the coefficients in the multipole expansion is then solved numerically. We generate dispersion diagrams for the two cases where the boundaries of holes are either clamped or free. We show that in the clamped case, there is a total low-frequency band gap in the limit of inclusions of zero radius, and give a simple formula describing the corresponding band diagram in this limit. We show that in the free-edge case, the band diagram of the vibrating plate is much closer to that of plane waves in a uniform plate than for the clamped case.

scholarly journals Low-Frequency Noise Spectroscopy of Bulk and Border Traps in Nanoscale Devices

2015 ◽  
Vol 242 ◽  
pp. 449-458 ◽  
Author(s):  
Eddy Simoen ◽  
Bogdan Cretu ◽  
Wen Fang ◽  
Marc Aoulaiche ◽  
Jean Marc Routoure ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Time Constant ◽  
Polycrystalline Silicon ◽  
Deep Level ◽  
Low Frequency ◽  
Silicon On Insulator ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Single Defect ◽  
Noise Spectroscopy

The principles and application of Generation-Recombination (GR) noise spectroscopy will be outlined and illustrated for the case of traps in Ultra-Thin Buried Oxide Silicon-on-Insulator nMOSFETs and for vertical polycrystalline silicon nMOSFETs. It will be shown that for scaled devices the GR noise is originating from a single defect, giving rise to a so-called Random Telegraph Signal (RTS). Several methods will be described for an accurate extraction of the RTS parameters (amplitude, up and down time constant). It will be demonstrated that besides the deep-level parameters also the position of the trap in the channel can be derived from a numerical modeling of the RTS amplitude.

MAGNETIC VORTEX BEHAVIOR IN NANO-STRUCTURES

2012 ◽  
Vol 23 (08) ◽  
pp. 1240003 ◽  
Author(s):  
B. V. COSTA ◽  
J. C. S. ROCHA ◽  
P. Z. COURA ◽  
S. A. LEONEL ◽  
D. TOSCANO ◽  
...  
Keyword(s):  
Ground State ◽  
Dynamical Behavior ◽  
Spin Valve ◽  
Magnetic Vortex ◽  
Magnetic Impurities ◽  
Nano Particle ◽  
Interaction Range ◽  
Single Defect ◽  
Nano Structures ◽  
Wide Range

The existence of a vortex in the ground state of magnetic nano-disks has open a wide range of possibilities for constructing new ultra-compact devices. In this work we study the dynamical behavior of a vortex in a magnetic nano-particle. First, we introduce magnetic impurities in the system. It is observed that depending on the strength of the interaction the impurities can behave both as a pinning (attractive) or scattering (repulsive). By using the known values of the parameters for Permalloy-79 we have calculated the interaction energy of the vortex core with a single defect. We estimated the interaction range as approximately 10 nm. Both results agree quite well with experimental measurements. As a second point we discuss how the vortex dynamics in nano-disks can be used for building a nano-spin valve.

scholarly journals Магнитно-резонансная силовая спектроскопия колебаний магнитного вихря

2020 ◽  
Vol 90 (11) ◽  
pp. 1821
Author(s):  
В.Л. Миронов ◽  
Е.В. Скороходов ◽  
Д.А. Татарский ◽  
И.Ю. Пашенькин
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Longitudinal Magnetic Field ◽  
Low Frequency ◽  
Inhomogeneous Magnetic Field ◽  
Magnetic Vortex ◽  
Significant Shift ◽  
Main Attention ◽  
Micromagnetic Modeling ◽  
Spectroscopy Studies

We present the results of micromagnetic modeling and experimental magnetic resonance force spectroscopy studies of forced magnetization oscillations in a circle NiFe disk in an external longitudinal magnetic field. The main attention is paid to the low-frequency resonance associated with the gyrotropic motion of the magnetic vortex core. It is shown that the applying external magnetic field in the plane of the sample leads to a significant shift in the resonance frequency of the gyrotropic mode. The influence of the inhomogeneous magnetic field of the probe on the peculiarities of the magnetization oscillations is discussed.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

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.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

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