On the road to faster and more efficient data storage

Date:
August 17, 2021
Source:
University of Konstanz
Summary:
A research team has discovered magnetic phenomena in
antiferromagnets that could pave the way to developing faster and
more efficient data storage.



FULL STORY ==========================================================================
A research team has discovered magnetic phenomena in antiferromagnets that could pave the way to developing faster and more efficient data storage.


==========================================================================
How do magnetic waves behave in antiferromagnets and how do they
spread? What role do "domain walls" play in the process? And what could
this mean for the future of data storage? These questions are the focus
of a recent publication in the journal Physical Review Letters from
an international research team led by Konstanz physicist Dr Davide
Bossini. The team reports on magnetic phenomena in antiferromagnets
that can be induced by ultrafast (femtosecond) laser pulses and with
the potential to endow the materials with new functionalities for energy-efficient and ultrafast data storage applications.

Demand for storage capacity is growing faster than the available
infrastructure The wildly increasing use of big data technologies and cloud-based data services means that the global demand for data storage
is constantly expanding -- along with the need for ever-faster data
processing. At the same time, the currently available technologies will
not be able to keep up forever. "The estimates say that the growing
demand can only be met for a limited period of about 10 years, if no
novel, more efficient technologies for data storage and processing can
be developed in the meantime," says physicist Dr Davide Bossini from
the University of Konstanz and lead author of the study.

To prevent a data crisis from taking place, it will not be enough
to simply keep building more and more data centres, operating at the
current state-of-the art. The technologies of the future must also be
faster and more energy- efficient than traditional mass data storage,
based on magnetic hard disks. One class of materials, antiferromagnets,
is a promising candidate for developing the next generation of information technology.

The structure of antiferromagnets We are all familiar with household
magnets made from iron or other ferromagnetic materials. These materials
have atoms that are magnetically all oriented in the same direction --
like small needles of a compass -- so that a magnetic polarization (magnetization) occurs that affects the surrounding environment. The antiferromagnets, by contrast, have atoms with alternating magnetic
moments that cancel each other out. Antiferromagnets thus have no
net magnetization and therefore no magnetic impact on the surrounding environment.



==========================================================================
On the inside, though, these antiferromagnetic bodies abundantly found in nature are split into many smaller areas called domains, where opposingly oriented magnetic moments are aligned in different directions. The
domains are separated from each other by transitional areas known as
"domain walls." "Although these transitional areas are well-known in antiferromagnets, until now, little was known about the influence the
domain walls have on the magnetic properties of antiferromagnets --
especially during extremely short time increments," says Dr Bossini.

Femtosecond magnetic phenomena In the current article, the researchers
describe what happens when antiferromagnets (more specifically: crystals
of nickel oxide) are exposed to ultrafast (femtosecond) laser pulses. The femtosecond scale is so short that even light can only move a very small distance in this period of time. In one quadrillionth of a second (one femtosecond), light travels a mere 0.3 micrometre -- equivalent to the
diameter of a small bacterium.

The international team of researchers showed that domain walls play an
active role in the dynamic properties of the antiferromagnet nickel
oxide. The experiments revealed that magnetic waves with different
frequencies could be induced, amplified and even coupled with each
other across different domains - - but only in the presence of domain
walls. "Our observations show that the ubiquitous presence of domain walls
in antiferromagnets could potentially be used to endow these materials
with new functionalities at the ultrafast scale," Bossini explains.

Important steps towards more efficient data storage The ability to couple different magnetic waves across domain walls highlights the potential
to actively control the propagation of magnetic waves in time and space
as well as energy transfer among individual waves at the femtosecond
scale. This is a pre-requisite for using these materials for the ultrafast storage and processing of data.

Such antiferromagnet-based data storage technologies would be several
orders of magnitude faster and more energy-efficient than current
ones. They would also be able to store and process a larger amount of
data. Since the materials have no net magnetization, they would also
be less vulnerable to malfunctions and external manipulation. "Future technologies based on antiferromagnets would thus meet all the
requirements for the next generation of data storage technology. They
also have the potential to keep pace with the growing demand for data
storage and processing capacity," concludes Bossini.

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


========================================================================== Journal Reference:
1. D. Bossini, M. Pancaldi, L. Soumah, M. Basini, F. Mertens,
M. Cinchetti,
T. Satoh, O. Gomonay, S. Bonetti. Ultrafast Amplification and
Nonlinear Magnetoelastic Coupling of Coherent Magnon Modes in
an Antiferromagnet.

Physical Review Letters, 2021; 127 (7) DOI: 10.1103/
PhysRevLett.127.077202 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/08/210817111401.htm

--- up 14 weeks, 4 days, 22 hours, 45 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)