Researchers demonstrate Hopfions emerging from skyrmions in magnetic multilayer systems

Recent studies have suggested that 2D skyrmions could be the genesis of a 3D spin pattern called hopfions, but no one had been able to experimentally prove that magnetic hopfions exist on the nanoscale. Now, a team of researchers co-led by Berkeley Lab reported the first demonstration and observation of 3D hopfions emerging from skyrmions at the nanoscale in a magnetic system.

Artist’s drawing of characteristic 3D spin texture of a magnetic hopfion imageArtist’s drawing of characteristic 3D spin texture of a magnetic hopfion. Berkeley Lab scientists have created and observed 3D hopfions. Credit: Peter Fischer and Frances Hellman/Berkeley Lab (from

The researchers say that their discovery is a major step forward in realizing high-density, high-speed, low-power, yet ultrastable magnetic memory devices that exploit the intrinsic power of electron spin.

Researchers report on electric field controlled motion in Skyrmions

Researchers from Shinshu University, the Chinese University of Hong Kong, the University of Tokyo, Tsinghua University, Kyoto University and Nanyang Technological University have experimentally demonstrated a breakthrough in manipulation of skyrmions using only electric field.

The team, led by Professor Xiaoxi Liu of Shinshu University, designed and fabricated magnetic multilayer films in the form of racetracks where the thickness of the films had a slope. They demonstrated that many skyrmion bubbles can be created and directionally displaced about 10 micrometres by applying a voltage as low as 9 volt in a repeatable manner. They also found that the domain wall displacement and velocity induced by the variation of electric field are proportional to the absolute value of voltage.

Researchers produce controllable and stable skyrmions using ultra-short laser pulses

Researchers from the EPFL managed to produce controllable and stable skyrmions using laser pulses. The scientists could write and erase skyrmions in less than a few hundred nanoseconds to a few microseconds.

To create the skyrmions, the researchers used iron-germanium alloy, which can offer skyrmions at about 0 degrees Celsius, very closet o room temperature. The ultra-short laser pulses create an ultra-fast temperature jump, and the super-cooling effect at the end of the jump restricts the place in which skyrmions exist - to places in which they do not exist normally.

Frustrated magnetic skyrmions may find applications in future spintronic devices

Researchers from Japan and China have discovered the exotic dynamics of frustrated magnetic skyrmions - which are different from that of magnetic skyrmions in common ferromagnetic materials. Magnetic skyrmions are very interesting for several spintronic applications, including magnetic memory and logic computing devices.

Skyrmions and antiskyrmions in a frustrated magnet photo

In conventional ferromagnetic materials, the helicity (degree of freedom) of a skyrmion cannot be effectively controlled, but the researchers found that in frustrated magnetic materials it is possible to control the skyrmion helicity by utilizing the helicity locking-unlocking transition of the material. The researcher further conclude that one can use frustrated skyrmions as a binary memory utilizing two stable Bloch-type states, where the helicity can be switched by applying current.

New film material enables to control and detect magnetic skyrmions

Researchers from Singapore's A*STAR and NTU developed a tunable room-temperature platform that can be used to control and detect magnetic skyrmions. This platform is actually a thin film made from multi-layer stacks of Ir/Fe/Co/Pt.

Magnetic skyrmions array (A*STAR)

In this material, the magnetic interactions governing skyrmion properties can be controlled by varying the ferromagnetic layer composition. The skyrmions exhibit a smooth crossover between isolated (metastable) and disordered lattice configurations across samples, while their size and density can be tuned by factors of two and ten, respectively.

MIT and JGU researchers advance towards skyrmion-based spintronics

Researchers from MIT and the Johannes Gutenberg University Mainz (JGU) achieved the billion-fold reproducible motion of skyrmions (special spin structures) between different positions. The researchers say that this kind of process is needed to produce magnetic shift registers - and so this is a critical step towards skyrmions applications in spintronics devices.

The magnetic structure of the skyrmion (image)

Using specially design thin film structures (asymmetric multilayer devices) that exhibit broken inversion symmetry that stabilize the skyrmions. In such structures, skyrmions have a unique stability - which makes them compelling for such spintronic devices. The researchers say that those skyrmions, that can be shifted by electrical currents and move relatively undisturbed through the track, are very promising to make racetrack devices.

JGU establishes a new spintronics junior research group

The Johannes Gutenberg University Mainz (JGU), with funding from the German Research Foundation (DFG), is setting up an Emmy Noether independent junior research group to study spintronics.

Skyrmions generated by hairy balls image

Specifically, the TWIST (Topological Whirls in SpinTronics) work group will study skyrmions - magnetic "particles" or nodes within a magnetic texture. Skyrmions are more stable than other magnetic structures and react particularly readily to spin currents - which makes them interesting for spintronics applications.

Skyrmions can be used to develop low-energy storage and logic devices

Researchers from Japan's RIKEN center discovered that skyrmions can be manipulated thermally using an electron beam. The researcher say that such a method could be used to develop low-energy memory and logic devices - in which the info is coded by the skyrmions.

In ferromagnetic materials, each atom acts like a tiny bar magnet. Usually all those "magnets" point in the same direction, but sometimes they can create skyrmions - "whirls" in the magnetic orientation of those atoms (see image above).

Researchers find magnetic skyrmions in atomically thin metal film

German researchers have found for the first time a regular lattice of magnetic skyrmions (cycloidal vortex spin structures of exceptional stability) – on a surface. This fascinating magnetic structure was discovered by spin-polarized scanning tunneling microscopy and imaged on the atomic scale.

The magnetic skyrmion lattice discovered in Hamburg occurs in an atomically thin film on a surface. The interplay of various magnetic interactions is the cause for the occurrence of this complex structure. While the canting of atomic spins with a certain rotational sense is caused by the antisymmetric Dzyaloshinskii-Moriya interaction, the skyrmions found here can only be induced by the so-called four-spin interaction with the participation of four magnetic atoms.