Scientists manipulate magnets at the atomic scale

February 12, 2021

Fast and energy-efficient future data processing technologies are on the horizon after an international team of scientists successfully manipulated magnets at the atomic level.

Physicist Dr Rostislav Mikhaylovskiy from Lancaster University said: "With stalling efficiency trends of current technology, new scientific approaches are especially valuable. Our discovery of the atomically-driven ultrafast control of magnetism opens broad avenues for fast and energy-efficient future data processing technologies essential to keep up with our data hunger."

Magnetic materials are heavily used in modern life with applications ranging from fridge magnets to Google and Amazon's data centers used to store digital information.

These materials host trillions of mutually aligned elementary magnetic moments or "spins", whose alignment is largely governed by the arrangement of the atoms in the crystal lattice.

The spin can be seen as an elementary "needle of a compass", typically depicted as an arrow showing the direction from North to South poles. In magnets all spins are aligned along the same direction by the force called exchange interaction. The exchange interaction is one of the strongest quantum effects which is responsible for the very existence of magnetic materials.

The ever-growing demand for efficient magnetic data processing calls for novel means to manipulate the magnetic state and manipulating the exchange interaction would be the most efficient and ultimately fastest way to control magnetism.

To achieve this result, the researchers used the fastest and the strongest stimulus available: ultrashort laser pulse excitation. They used light to optically stimulate specific atomic vibrations of the magnet's crystal lattice which extensively disturbed and distorted the structure of the material.

The results of this study are published in the prestigious journal Nature Materials by the international team from Lancaster, Delft, Nijmegen, Liege and Kiev.

PhD student Jorrit Hortensius from the Technical University of Delft said: "We optically shake the lattice of a magnet that is made up of alternating up and down small magnetic moments and therefore does not have a net magnetization, unlike the familiar fridge magnets."

After shaking the crystal for a very short period of time, the researchers measured how the magnetic properties evolve directly in time. Following the shaking, the magnetic system of the antiferromagnet changes, such that a net magnetization appears: for a fraction of time the material becomes similar to the everyday fridge magnets.

This all occurs within an unprecedentedly short time of less than a few picoseconds (millionth of a millionth of a second). This time is not only orders of magnitude shorter than the recording time in modern computer hard drives, but also exactly matches the fundamental limit for the magnetization switching.

Dr Rostislav Mikhaylovskiy from Lancaster University explains: "It has long been thought that the control of magnetism by atomic vibrations is restricted to acoustic excitations (sound waves) and cannot be faster than nanoseconds. We have reduced the magnetic switching time by 1000 times that is a major milestone in itself."

Dr Dmytro Afanasiev from the Technical University of Delft adds: "We believe that our findings will stimulate further research into exploring and understanding the exact mechanisms governing the ultrafast lattice control of the magnetic state."

Lancaster University

Related Magnetism Articles from Brightsurf:

Connecting two classes of unconventional superconductors
The understanding of unconventional superconductivity is one of the most challenging and fascinating tasks of solid-state physics.

Stacking and twisting graphene unlocks a rare form of magnetism
A team of researchers at Columbia University and the University of Washington has discovered that a variety of exotic electronic states, including a rare form of magnetism, can arise in a three-layer graphene structure.

Finding the right colour to control magnets with laser pulses
Scientists have discovered a new way to manipulate magnets with laser light pulses shorter than a trillionth of a second.

Quirky response to magnetism presents quantum physics mystery
In a new study just published and highlighted as an Editor's Suggestion in Physical Review Letters, scientists describe the quirky behavior of one such magnetic topological insulator.

Story tips: Cool smart walls, magnetism twist, fuel cost savings and polymers' impact
ORNL Story Tips: Cool smart walls, magnetism twist, fuel cost savings and polymers' impact, September 2020

When Dirac meets frustrated magnetism
Scientists at the Max Planck Institute of Microstructure Physics have discovered one of the largest anomalous Hall effects (15,506 siemens per centimeter at 2 Kelvin) ever observed in the new compound, KV3Sb5.

Scientists use pressure to make liquid magnetism breakthrough
Scientists have forced a solid magnetic metal into a spin liquid state, which may lead to insights into superconductivity and quantum computing.

Unraveling the magnetism of a graphene triangular flake
Graphene is a diamagnetic material, this is, unable of becoming magnetic.

A twist connecting magnetism and electronic-band topology
Materials that combine topological electronic properties and quantum magnetism are of high current interest, for the quantum many-body physics that can unfold in them and for possible applications in electronic components.

How to induce magnetism in graphene
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechani-cal, electronic and optical properties.

Read More: Magnetism News and Magnetism Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to