Exotic magnetic structures created with laser light

Date:
April 25, 2022
Source:
Lund University
Summary:
Research has found a new way to create nano-sized magnetic particles
using ultrafast laser light pulses. The discovery could pave the
way for new and more energy-efficient technical components and
become useful in the quantum computers of the future.



FULL STORY ========================================================================== Research at Lund University in Sweden has found a new way to create
nano-sized magnetic particles using ultrafast laser light pulses. The
discovery could pave the way for new and more energy-efficient technical components and become useful in the quantum computers of the future.


========================================================================== Magnetic skyrmions are sometimes described as magnetic vortices. Unlike ferromagnetic states -- which occur in conventional magnets such
as compasses and refrigerator magnets -- the skyrmion state is quite
peculiar: the orientation of the magnetization does not point in the same direction everywhere in the material, but is instead best described as
a kind of swirling magnetism.

Skyrmions are of great interest to both basic researchand industry, as
they can be used to manufacture more compact computer memories. However,
that is easier said than done. Using skyrmions for technical purposes
requires efficient ways of writing, erasing and manipulating the particles
on short time scales, and with high spatial precision.

In a new study, researchersClaudio Verdozzi from Lund University and
Emil Vin~as Bostro"m and Angel Rubio from the Max Planck Institute for
the Structure and Dynamics of Matter in Hamburg have found a new approach.

"In our study, we have theoretically shown how it is possible to meet
one of these requirements, that is, how to create magnetic skyrmions
in ultra-short time scales using pulses of laser light," says Claudio
Verdozzi, physics researcher at Lund University.

The research team has identified a microscopic mechanism that explains
an experimental protocol that has been shown to be useful in creating
the strange skyrmions. Using femtosecond laser pulses -- light pulses
that last one millionth of a billionth of a second -- the researchers
showed that it is possible to create skyrmions ultra-fast.

"Our results are of great relevance to creating more energy-efficient
technical components. Our study shows that light can be used to manipulate localized magnetic excitations in very short time scales," says Claudio Verdozzi.

There are a number of applications that the new discovery can lead
to, including quantum technology -- an area where quantum mechanical
properties are used to solve extremely advanced calculations that
traditional computers cannot handle. Magnetic excitations such as
skyrmions and so-called spin waves are also believed to be able to help
reduce energy consumption in technological components, and can thus help
to achieve future climate goals.

"Skyrmions are in focus for both theoretical and experimental research
thanks to their technological potential. Also, their exotic magnetic
patterns possess a conceptually and mathematically beautiful appeal that
makes them very interesting," concludes Claudio Verdozzi.


========================================================================== Story Source: Materials provided by Lund_University. Note: Content may
be edited for style and length.


========================================================================== Journal Reference:
1. Emil Vin~as Bostro"m, Angel Rubio, Claudio Verdozzi. Microscopic
theory
of light-induced ultrafast skyrmion excitation in transition
metal films.

npj Computational Materials, 2022; 8 (1) DOI:
10.1038/s41524-022-00735-5 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220425104858.htm

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