Femtosecond laser driven precessing magnetic gratings.

Nanoscale

Materials and Nano Physics, Department of Applied Physics, KTH Royal Institute of Technology, Kista, Sweden.

Published: February 2021

Manipulation and detection of spins at the nanoscale is of considerable contemporary interest as it may not only facilitate a description of fundamental physical processes but also plays a critical role in the development of spintronic devices. Here, we describe the application of a novel combination of transient grating excitation with Lorentz ultrafast electron microscopy to control and detect magnetization dynamics with combined nanometer and picosecond resolutions. Excitation of Ni80Fe20 thin film samples results in the formation of transient coherently precessing magnetic gratings. From the time-resolved results, we extract detailed real space information of the magnetic precession, including local magnetization, precession frequency, and relevant decay factors. The Lorentz contrast of the dynamics is sensitive to the alignment of the in-plane components of the applied field. The experimental results are rationalized by a model considering local demagnetization and the phase of the precessing magnetic moments. We envision that this technique can be extended to the study of spin waves and dynamic behavior in ferrimagnetic and antiferromagnetic systems.

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0nr07962fDOI Listing

Publication Analysis

Top Keywords

precessing magnetic
12
magnetic gratings
8
femtosecond laser
4
laser driven
4
driven precessing
4
magnetic
4
gratings manipulation
4
manipulation detection
4
detection spins
4
spins nanoscale
4

Similar Publications

Improving Image Quality and Decreasing SAR With High Dielectric Constant Pads in 3 T Fetal MRI.

J Magn Reson Imaging

January 2025

Department of Radiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, Jiangsu, China.

Background: At high magnetic fields, degraded image quality due to dielectric artifacts and elevated specific absorption rate (SAR) are two technical challenges in fetal MRI.

Purpose: To assess the potential of high dielectric constant (HDC) pad in increasing image quality and decreasing SAR for 3 T fetal MRI.

Study Type: Prospective.

View Article and Find Full Text PDF

Low-frequency noise in detection systems significantly affects the performance of ultrasensitive and ultracompact spin-exchange relaxation-free atomic magnetometers. High frequency modulation detection helps effectively suppress the 1/ noise and enhance the signal-to-noise ratio, but conventional modulators are bulky and restrict the development of integrated atomic magnetometer modulation-detection systems. Resonant metasurface-based thin-film lithium-niobate (TFLN) active optics can modulate free-space light within a compact configuration.

View Article and Find Full Text PDF

Magnetization switching by charge current without a magnetic field is essential for device applications and information technology. It generally requires a current-induced out-of-plane spin polarization beyond the capability of conventional ferromagnet/heavy-metal systems, where the current-induced spin polarization aligns in-plane orthogonal to the in-plane charge current and out-of-plane spin current. Here, a new approach is demonstrated for magnetic-field-free switching by fabricating a van-der-Waals magnet and oxide FeGeTe/SrTiO heterostructure.

View Article and Find Full Text PDF

Purpose: This study proposes a novel, contrast-free Magnetic Resonance Fingerprinting (MRF) method using balanced Steady-State Free Precession (bSSFP) sequences for the quantification of cerebral blood volume (CBV), vessel radius (R), and relaxometry parameters (T , T , T *) in the brain.

Methods: The technique leverages the sensitivity of bSSFP sequences to intra-voxel frequency distributions in both transient and steady-state regimes. A dictionary-matching process is employed, using simulations of realistic mouse microvascular networks to generate the MRF dictionary.

View Article and Find Full Text PDF

Ultra-high-resolution brain MRI at 0.55T: bSTAR and its application to magnetization transfer ratio imaging.

Z Med Phys

January 2025

Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland; Department of Radiology, Division of Radiological Physics, University Hospital Basel, Basel, Switzerland.

Purpose: This study aims to evaluate the feasibility of structural sub-millimeter isotropic brain MRI at 0.55 T using a 3D half-radial dual-echo balanced steady-state free precession sequence, termed bSTAR and to assess its potential for high-resolution magnetization transfer imaging.

Methods: Phantom and in-vivo imaging of three healthy volunteers was performed on a low-field 0.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!