KAIST Reveals the Formation Mechanism of Skyrmions Inside Magnets… A Clue to Solving AI Power Consumption
<(From Left) Prof.Se Kwon Kim, Dr. Gyungchoon Go>
“Skyrmions,” in which electron spins inside a magnet are arranged like vortices, are a key structure in next-generation spintronics technology. KAIST researchers have shown that skyrmions can form using only the fundamental physical interactions within magnets, without requiring special physical conditions. This finding expands the possibility of realizing skyrmions in a wide range of magnetic materials and suggests new potential for developing next-generation ultra-low-power information devices with data storage densities tens to hundreds of times higher than current technologies.
KAIST (President Kwang Hyung Lee) announced on the 19th of March that a research team led by Professor Se Kwon Kim from the Department of Physics has proposed a new theoretical framework showing that vortex-like magnetic structures can naturally emerge solely through magnetoelastic coupling—the interaction between magnetism and lattice structure.
The team demonstrated that the interaction between spins (the intrinsic magnetic property of electrons) and lattice deformation (the slight distortion of atomic arrangements) alone can lead to the spontaneous formation of vortex-like magnetic structures.
In particular, skyrmions—vortex-like spin structures found inside magnetic materials—are extremely small and highly stable, making them promising candidates for ultra-high-density, low-power information devices. However, until now, forming such structures was believed to require specific physical conditions such as crystal asymmetry or strong spin–orbit coupling.
The researchers theoretically showed that even without such special conditions, magnetoelastic coupling, which naturally occurs in most magnetic materials, is sufficient to generate a structure in which skyrmions and antiskyrmions are alternately arranged.
Magnetoelastic coupling refers to the phenomenon in which magnetism (spin) and lattice deformation influence each other, and it is a fundamental physical property present in nearly all magnetic materials. The team showed that when this coupling becomes sufficiently strong, the original ground state—where magnetization is uniformly aligned—becomes unstable and transitions into a new vortex-like ordered state.
In this process, they proposed a new mechanism in which spin tilting and lattice distortion occur simultaneously, forming a chiral spin texture composed of alternating skyrmions and antiskyrmions.
Professor Se Kwon Kim explained, “This study demonstrates that skyrmion-like magnetic structures can form even without specific or exotic interactions. It is particularly meaningful in that it suggests the possibility of realizing such structures in two-dimensional magnetic materials, where research is currently very active.”
This study was led by Gyungchoon Go, who participated as the first author. The research was published on February 11 in the internationally renowned journal Physical Review Letters, recognizing its significance in the field of physics.
※ Paper title: “Magnetoelastic Coupling-Driven Chiral Spin Textures: A Skyrmion-Antiskyrmion-like Array,” DOI:https://doi.org/10.1103/5csz-pw7x
※ Main Authors: Gyungchoon Go (first author), Se Kwon Kim (corresponding author)
This research was supported by the Samsung Science and Technology Foundation, the Brain Pool Plus Program by the National Research Foundation of Korea, and the Sejong Science Fellowship.
Research Finds Digital Music Streaming Consumption Dropped as a Result of Covid-19 and Lockdowns
Decline in human mobility has stunning consequences for content streaming
The Covid-19 pandemic and lockdowns significantly reduced the consumption of audio music streaming in many countries as people turned to video platforms. On average, audio music consumption decreased by 12.5% after the World Health Organization’s (WHO) pandemic declaration in March 2020.
Music streaming services were an unlikely area hit hard by the Covid-19 pandemic. New research in Marketing Science found that the drop in people’s mobility during the pandemic significantly reduced the consumption of audio music streaming. Instead, people turned more to video platforms.
“On average, audio music consumption decreased by more than 12% after the World Health Organization’s (WHO) pandemic declaration on March 11, 2020. As a result, during the pandemic, Spotify lost 838 million dollars of revenue in the first three quarters of 2020,” said Jaeung Sim, a PhD candidate in management engineering at KAIST and one of the authors of the research study on this phenomenon. “Our results showed that human mobility plays a much larger role in the audio consumption of music than previously thought.”
The study, “Frontiers: Virus Shook the Streaming Star: Estimating the Covid-19 Impact on Music Consumption,” conducted by Sim and Professor Daegon Cho of KAIST, Youngdeok Hwang of City University of New York, and Rahul Telang of Carnegie Mellon University, looked at online music streaming data for top songs for two years in 60 countries, as well as Covid-19 cases, lockdown statistics, and daily mobility data, to determine the nature of the changes.
The study showed how the pandemic adversely impacted music streaming services despite the common expectation that the pandemic would universally benefit online medias platforms. This implies that the substantially changing media consumption environment can place streaming music in fiercer competition with other media forms that offer more dynamic and vivid experiences to consumers.
The researchers found that music consumption through video platforms was positively associated with the severity of Covid-19, lockdown policies, and time spent at home.
-PublicationJaeung Sim, Daegon Cho, Youngdeok Hwang, and Rahul Telang,“Frontiers: Virus Shook the Streaming Star: Estimating the Covid-19 Impact on Music Consumption,” November 30 in Marketing Science online (doi.org/10.1287/mksc.2021.1321)
-Profile Professor Daegon ChoGraduate School of Information and Media ManagementCollege of BusinessKAIST
Seung-Han Lee, a doctoral student in electrical engineering, receives the best paper award from ISQED 2014
Seung-Han
Lee, a doctoral candidate in the department of electrical engineering at KAIST,
received a Best Paper Award from the International Symposium on Quality
Electronic Design (ISQED), a high-profile international conference started in 2000 to promote innovation and quality in electronic and
engineering designs through inter- and multidisciplinary approaches. The
award ceremony will take place at the 2014 ISQED on March 3-5, 2014 at the Convention
Center in Santa Clara, CA, USA.
Professor
Chong-Min Kyung, an advisor to Seung-Han, expressed his excitement about his student's achievement.
“This is
the first time a Korean has ever received the best paper award at this academic
conference. It’s great news to our student as well as to KAIST.”
The topic
of Lee’s research paper was dynamic cache data management for minimizing the
energy consumption of three-dimensional multi-processor semiconductor chips.
Prototype technologies for world highest efficiency PDP lightening developed by Prof. Choi
- Core technologies that will solve power consumption problems in PDPs- To be unveiled as invited paper at conference by Society for Information Display in May
A domestic research team has developed prototype technologies for high efficiency lightening that can significantly improve the power consumption of Plasma Display Panels (PDP).
A team headed by Kyung Cheol Choi, a professor of Electrical & Computer Science in KAiST (President Nam-Pyo Suh), has developed new cell structures and driving methods of PDP, typical digital television, which can increase the luminous efficacy of PDP four times and are to be unveiled at the conference by the Society for Information Display (SID) as an invited paper. The SID is the world largest information display society and the conference will be held at Long Beach, CA, U.S. on May 21.
Prof. Choi