Research Activities

[Suyoung Lee and Prof. Changyoung Kim] Broken Kramers Degeneracy in Altermagnetic MnTe (published in... Jan 22, 2024 l Hit 241

“Broken Kramers Degeneracy in Altermagnetic MnTe” Altermagnetism is a newly identified fundamental class of magnetism with vanishing net magnetization and time-reversal symmetry broken electronic structure. Probing the unusual electronic structure with nonrelativistic spin splitting would be a...

[Ha-Leem Kim,  Heejun Yang, and Prof.  Je-Geun Park] Thermal Hall effects due to topological spin flu... Jan 4, 2024 l Hit 225

The thermal Hall effect in magnetic insulators has been considered a powerful method for examining the topological nature of charge-neutral quasiparticles such as magnons. Yet, unlike the kagome system, the triangular lattice has received less attention for studying the thermal Hall effect because the scalar spin chira...

[Dr. Kai-Xuan Zhang / Prof. Je-Geun Park]  Broken Inversion Symmetry in Van Der Waals Topological Fe... Jan 2, 2024 l Hit 194

Inversion symmetry breaking is critical for many quantum effects and fundamental for spin-orbit torque, which is crucial for next-generation spintronics. Recently, a novel type of gigantic intrinsic spin-orbit torque has been established in the topological van-der-Waals (vdW) magnet iron germanium telluride. However, i...

[Dr. Tae-Yun Lee & Prof. Heonsu Jeon] Resonant cavity phosphor (Published in Nature Communications) Oct 25, 2023 l Hit 145

While phosphors play an immensely important role in solid-state lighting and full-colour displays, it has been noted lately that their performance can be largely improved via structural engineering. Here, phosphor material is synergistically merged with yet another structurally engineered platform, reson...

[Donghan Kim, Younsik Kim and Prof. Changyoung Kim] Electric control of Two-Dimensional Van Hove Sin... Mar 21, 2023 l Hit 359

Divergent density of states (DOS) can induce extraordinary phenomena such as significant enhancement of superconductivity and unexpected phase transitions. Moreover, van Hove singularities (VHSs) lead to divergent DOS in two-dimensional (2D) systems. Despite recent interest in VHSs, only a few controllable cases have b...

[KW An's Group] A photonic quantum engine driven by superradiance Jul 25, 2022 l Hit 1873

Performance of nano- and microscale heat engines can be improved with the help of quantum-mechanical phenomena. Recently, heat reservoirs with quantum coherence have been proposed to enhance engine performance beyond the Carnot limit even with a single reservoir. However, no physical realizations have been achieved so ...

[Kyeong-Yoon Baek, Dr. Jeongjae Lee, Prof. Tae-Woo Lee, Prof. Keehoon Kang & Prof. Takhee Lee] Mecha... Jul 25, 2022 l Hit 1214

Embedding metal–halide perovskite particles within an insulating host matrix has proven to be an effective strategy for revealing the outstanding luminescence properties of perovskites as an emerging class of light emitters. Particularly, unexpected bright green emission observed in a nominally pure zero-dimensio...

[Daeho Yang, Seunghoon Oh, Junseok Han, Gibeom Son, Jinuk Kim and Kyungwon An] Realization of supera... Mar 8, 2021 l Hit 1356

Superabsorption refers to a 'super' version of absorption just like superradiance is a 'super' version of emission. In superabsorption, correlated atoms collectively absorb light. The light can be absorbed completely and the number of absorbed photons is proportional to the square of the number of atoms. Although super...

[Keehoon Kang, Prof. Takhee Lee] Layer-by-Layer Structural Identification of 2D Ruddlesden–Popper Hy... Jan 28, 2021 l Hit 799

Application of two-dimensional (2D) organic–inorganic hybrid halide perovskites in optoelectronic devices requires a detailed understanding of the local structural features including the Pb–I bonding in the 2D layers and the organic–inorganic interaction between the organic spacer molecules and the pe...

Momentum-dependent magnon lifetime in the metallic non-collinear triangular antiferromagnet CrB2 Jul 9, 2020 l Hit 1538

Noncollinear magnetic order arises for various reasons in several magnetic systems and exhibits interesting spin dynamics. Despite its ubiquitous presence, little is known of how magnons, otherwise stable quasiparticles, decay in these systems, particularly in metallic magnets. Using inelastic neutron scattering, we ex...