Unraveling ultrafast magnetization dynamics of nanoscale magnetic textures
Abstract
Solid-state electronic devices are based on the manipulation of electric charges to perform computing operations, an approach that is quickly reaching its limitation in avenues such as speed limit, miniaturization, and energy efficiency. Optical manipulation of magnetic materials, whereby spin is controlled via ultrafast laser pulses has emerged as a novel way to address these limitations. It has been shown that a magnet can lose its magnetization within approximate100 femtosecond (fs), which is 3-4 order of magnitude faster than current devices. However, the fundamental understanding underlying the ultrafast control of magnetization dynamics is still lacking and the mechanisms through which a magnetic system can dissipate angular momentum at such fast timescales are widely debated. Furthermore, most of the studies have focused on homogeneously magnetic systems and studies on the nanoscale magnetic textures have been limited. One of the key reasons is the lack of experimental techniques which can access both fs timescales and nanometer lengthscales. We will utilize coherent x-ray based approach following laser excitation to directly image modification of nanoscale magnetic textures at ultrafast timescales and identify different contributions for angular momentum dissipation resulting in ultrafast magnetization dynamics. The key objectives of this proposal are, (1) directly imaging modification of nanoscale magnetic textures at fs timescales following laser excitation, (2) utilizing x-ray methods to quantify spin transport in magnetic multilayers, and (3) determining the role of electron-magnon and electron-phonon scattering mechanisms in modification of magnetic textures. These studies will provide unified understanding of magnetization control and limits associated with magnetization reversal at ultrafast and ultra small frontier. The proposed studies will pave the way for development of optimal material design and manipulating magnetism which are critically needed for development of laser based building blocks for future computing system.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 06, 2024
- Source ID
- FA95502310395
Entities
People
- Roopali Kukreja
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, Davis