Ultrafast Magnetization Reversal Dynamics on A Micrometer-Scale Thin Film Element Studied by Time Domain Imaging

2000 ◽  
Vol 648 ◽  
Author(s):  
B.C. Choi ◽  
G. Ballentine ◽  
M. Belov ◽  
W.K. Hiebert ◽  
M.R. Freeman
Keyword(s):  
Domain Wall ◽  
Time Domain ◽  
Magnetization Reversal ◽  
Switching Time ◽  
Magnetization Vector ◽  
Domain Wall Motion ◽  
Time Resolved ◽  
Imaging Results ◽  
Resonance Frequencies ◽  
The Time Domain

AbstractPicosecond time scale magnetization reversal dynamics in a 15nm thick Ni80Fe20 microstructure (10μm×2μm) is studied using time-resolved scanning Kerr microscopy. The time domain images reveal a striking change in the magnetization reversal mode, associated with the dramatic reduction in switching time when the magnetization vector is pulsed by a longitudinal switching field while a steady transverse biasing field is applied to the sample. According to the time domain imaging results, the abrupt change of the switching time is due to the change in the magnetization reversal mode; i.e., the nucleation dominant reversal process is replaced by domain wall motion if transverse biasing field is applied. Furthermore, magnetization oscillations subsequent to reversal are observed at two distinct resonance frequencies, which sensitively depend on the biasing field strength. The high frequency resonance at f=2 GHz is caused by damped precession of the magnetization vector, whereas another mode at f≈0.8 GHz is observed to arise from domain wall oscillation.

scholarly journals Time-resolved tympanal mechanics of the locust

2008 ◽  
Vol 5 (29) ◽  
pp. 1435-1443 ◽  
Author(s):  
J.F.C Windmill ◽  
S Bockenhauer ◽  
D Robert
Keyword(s):  
Time Domain ◽  
Travelling Waves ◽  
Time Resolved ◽  
Wave Resonance ◽  
Salient Characteristic ◽  
Mechanosensory Neurons ◽  
Auditory Systems ◽  
Tympanal Membrane ◽  
The Time Domain ◽  
First Time

A salient characteristic of most auditory systems is their capacity to analyse the frequency of sound. Little is known about how such analysis is performed across the diversity of auditory systems found in animals, and especially in insects. In locusts, frequency analysis is primarily mechanical, based on vibrational waves travelling across the tympanal membrane. Different acoustic frequencies generate travelling waves that direct vibrations to distinct tympanal locations, where distinct groups of correspondingly tuned mechanosensory neurons attach. Measuring the mechanical tympanal response, for the first time, to acoustic impulses in the time domain, nanometre-range vibrational waves are characterized with high spatial and temporal resolutions. Conventional Fourier analysis is also used to characterize the response in the frequency domain. Altogether these results show that travelling waves originate from a particular tympanal location and travel across the membrane to generate oscillations in the exact region where mechanosensory neurons attach. Notably, travelling waves are unidirectional; no strong back reflection or wave resonance could be observed across the membrane. These results constitute a key step in understanding tympanal mechanics in general, and in insects in particular, but also in our knowledge of the vibrational behaviour of anisotropic media.

Time-Resolved X-Ray Scattering from Coherent Excitations in Solids

MRS Bulletin ◽  
2010 ◽  
Vol 35 (7) ◽  
pp. 514-519 ◽  
Author(s):  
Mariano Trigo ◽  
David Reis
Keyword(s):  
Time Domain ◽  
Free Electron Laser ◽  
Femtosecond Lasers ◽  
Light Sources ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Far From Equilibrium ◽  
The Time Domain ◽  
Ray Scattering

AbstractRecent advances in pulsed x-ray sources have opened up new opportunities to study the dynamics of matter directly in the time domain with picosecond to femtosecond resolution. In this article, we present recent results from a variety of ultrafast sources on time-resolved x-ray scattering from elementary excitations in periodic solids. A few representative examples are given on folded acoustic phonons, coherent optical phonons, squeezed phonons, and polaritons excited by femtosecond lasers. Next-generation light sources, such as the x-ray-free electron laser, will lead to improvements in coherence, flux, and pulse duration. These experiments demonstrate potential opportunities for studying matter far from equilibrium on the fastest time scales and shortest distances that will be available in the coming years.

scholarly journals Development of a High-Speed Digitizer to Time Resolve Nanosecond Fluorescence Pulses

2012 ◽  
Vol 10 (2) ◽  
Author(s):  
E. Moreno-García ◽  
R. Galicia-Mejía ◽  
D. Jiménez-Olarte ◽  
J. M. de la Rosa Vázquez ◽  
S. Stolik-Isakina
Keyword(s):  
Time Domain ◽  
Digital Signal Processor ◽  
High Speed ◽  
High Performance ◽  
Input Pulse ◽  
Control Program ◽  
Sampling Technique ◽  
Digital Signal ◽  
Time Resolved ◽  
The Time Domain

The development of a high-speed digitizer system to measure time-domain voltage pulses in nanoseconds range is presented in this work. The digitizer design includes a high performance digital signal processor, a high-bandwidth analog-to-digital converter of flash-type, a set of delay lines, and a computer to achieve the time-domain measurements. A program running on the processor applies a time-equivalent sampling technique to acquire the input pulse. The processor communicates with the computer via a serial port RS-232 to receive commands and to transmit data. A control program written in LabVIEW 7.1 starts an acquisition routine in the processor. The program reads data from processor point by point in each occurrence of the signal, and plots each point to recover the time-resolved input pulse after n occurrences. The developed prototype is applied to measure fluorescence pulses from a homemade spectrometer. For this application, the LabVIEW program was improved to control the spectrometer, and to register and plot time-resolved fluorescence pulses produced by a substance. The developed digitizer has 750 MHz of analog input bandwidth, and it is able to resolve 2 ns rise-time pulses with 150 ps of resolution and a temporal error of 2.6 percent.

scholarly journals Progress of electrical control magnetization reversal and domain wall motion

2017 ◽  
Vol 66 (2) ◽  
pp. 027501
Author(s):  
Zhang Nan ◽  
Zhang Bao ◽  
Yang Mei-Yin ◽  
Cai Kai-Ming ◽  
Sheng Yu ◽  
...  
Keyword(s):  
Domain Wall ◽  
Magnetization Reversal ◽  
Wall Motion ◽  
Domain Wall Motion ◽  
Electrical Control

scholarly journals Lifetime encoding in flow cytometry for bead-based sensing of biomolecular interaction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Kage ◽  
Katrin Hoffmann ◽  
Heike Borcherding ◽  
Uwe Schedler ◽  
Ute Resch-Genger
Keyword(s):  
Flow Cytometry ◽  
Time Domain ◽  
High Throughput Screening ◽  
Photon Counting ◽  
Clinical Diagnostics ◽  
Biomolecular Interactions ◽  
Time Resolved ◽  
Excitation Light ◽  
Intensity Measurements ◽  
The Time Domain

Abstract To demonstrate the potential of time-resolved flow cytometry (FCM) for bioanalysis, clinical diagnostics, and optically encoded bead-based assays, we performed a proof-of-principle study to detect biomolecular interactions utilizing fluorescence lifetime (LT)-encoded micron-sized polymer beads bearing target-specific bioligands and a recently developed prototype lifetime flow cytometer (LT-FCM setup). This instrument is equipped with a single excitation light source and different fluorescence detectors, one operated in the photon-counting mode for time-resolved measurements of fluorescence decays and three detectors for conventional intensity measurements in different spectral windows. First, discrimination of bead-bound biomolecules was demonstrated in the time domain exemplarily for two targets, Streptavidin (SAv) and the tumor marker human chorionic gonadotropin (HCG). In a second step, the determination of biomolecule concentration levels was addressed representatively for the inflammation-related biomarker tumor necrosis factor (TNF-α) utilizing fluorescence intensity measurements in a second channel of the LT-FCM instrument. Our results underline the applicability of LT-FCM in the time domain for measurements of biomolecular interactions in suspension assays. In the future, the combination of spectral and LT encoding and multiplexing and the expansion of the time scale from the lower nanosecond range to the longer nanosecond and the microsecond region is expected to provide many distinguishable codes. This enables an increasing degree of multiplexing which could be attractive for high throughput screening applications.

Effect of stripe domains on magnetization reversal and domain wall motion-like boundary expansion of the stripe domain region

2020 ◽  
Vol 53 (28) ◽  
pp. 285001
Author(s):  
Xiaolei Li ◽  
Hongkang Xie ◽  
Yurui Wei ◽  
Hongmei Feng ◽  
Yueyue Liu ◽  
...  
Keyword(s):  
Domain Wall ◽  
Magnetization Reversal ◽  
Wall Motion ◽  
Domain Wall Motion ◽  
Stripe Domain
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