A5100359395- Surface and Thin Film Phenomena
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Graphene research and applications
- 2D Materials and Applications
- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Molecular Junctions and Nanostructures
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Semiconductor materials and interfaces
- Force Microscopy Techniques and Applications
- Copper Interconnects and Reliability
- X-ray Diffraction in Crystallography
- Iron-based superconductors research
- Nanowire Synthesis and Applications
- Crystallization and Solubility Studies
- Organic and Molecular Conductors Research
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Nanopore and Nanochannel Transport Studies
- Advanced Sensor and Energy Harvesting Materials
- Advanced Materials Characterization Techniques
- Inorganic Chemistry and Materials
- Rare-earth and actinide compounds
Pohang University of Science and Technology
2014-2025
Samsung (South Korea)
2003-2025
Sogang University
2025
Kyung Hee University
2024
Korea Foundation for Max Planck POSTECH
2020-2023
Sungkyunkwan University
2022
Korea University
2020
Daegu Gyeongbuk Institute of Science and Technology
2019
Kwangwoon University
2019
Incheon National University
2019
Abstract Camouflage is an emerging application of metamaterials owing to their exotic electromagnetic radiative properties. Based on the use a selective emitter and absorber as metamaterials, most reported articles have suggested single‐band camouflage, however, multispectral camouflage challenging issue difference several orders magnitude in unit cell structure. Herein, hierarchical (HMMs) for signal control when dissipating absorbed energy microwaves through emission infrared (IR) waves...
Copper is the current interconnect metal of choice in integrated circuits. As dimensions decrease, resistivity copper increases dramatically because electron scattering from surfaces, impurities, and grain boundaries (GBs) threatens to stymie continued device scaling. Lacking direct measurements individual sources, understanding relative importance these mechanisms has largely relied on semiempirical modeling. Here we present first ever attempt measure calculate GB resistances nanowires with...
Handedness at the edge of a line Topological insulators are characterized by conducting boundary states. For those existing as two-dimensional (2D) materials, boundaries lines, currents 1D, and their two spin components flow in opposite directions. To address whether this handedness also applies to states 1D topological systems, Cheon et al. deposited indium atoms on surface silicon, where formed wires consisting double zigzag chains. The chains underwent distortions that caused called...
Enhancing the critical heat flux (CHF), which is capacity of dissipation, important to secure high stability in two-phase cooling systems. Coolant supply a dry hot spot major mechanism prevent surface burn-out for enhancing CHF. Here, we demonstrate more ready coolant using aligned silicon nanowires (A-SiNWs), with aspect ratio (>10) compared that conventional random (R-SiNWs), have disordered arrangement, additional CHF improvement. We propose volumetric wicking rate, represents properties...
Chirality-driven optical properties in charge density waves are of fundamental and practical importance. Here, we investigate the interaction between circularly polarized light emergent chiral stacking orders quasi-one-dimensional (quasi-1D) charge-density (CDWs) with density-functional theory calculations. In our specific system, self-assembled nanowires on a Si(111) surface, spontaneous mirror symmetry breaking leads to four symmetrically distinct degenerate quasi-1D CDW structures, which...
The electronic states of a single Bi(111) bilayer and its edges, suggested as two dimensional topological insulator, are investigated by scanning tunneling spectroscopy (STS) first-principles calculations. Well-ordered films islands with zigzag edges grown epitaxially on cleaved Bi$_{2}$Te$_{2}$Se crystal. calculation shows that the band gap Bi closes formation new but small hybridization due to strong interaction between Bi$_{2}$Te$_{2}$Se. Nevertheless, nature edge state preserved only an...
Atomically thin nanosheets, as recently realized using van der Waals layered materials, offer a versatile platform for studying the stability and tunability of correlated electron phases in reduced dimension. Here, we investigate thickness-dependent excitonic insulating (EI) phase on ternary chalcogenide Ta2NiSe5. Using Raman spectroscopy, scanning tunneling in-plane transport measurements, found no significant changes crystalline electronic structures well disorder strength ultrathin...
Spin–orbit coupling results in technologically-crucial phenomena underlying magnetic devices like memories and energy-efficient motors. In heavy element materials, the strength of spin–orbit becomes large to affect overall electronic nature induces novel states such as topological insulators spin–orbit-integrated Mott states. Here we report an unprecedented charge-ordering cascade IrTe2 without loss metallicity, which involves localized with diamagnetic Ir4+–Ir4+ dimers. The cooling,...
Artificial camouflage surfaces for assimilating with the environment have been utilized controlling optical properties. Especially, properties of infrared (IR) materials should be satisfied two requirements: deception IR signature in a detected band through reduced emissive energy and dissipation preventing thermal instability an undetected band. Most reported articles suggest reduction band; however, broadband emission enough simultaneously is still challenging issue. Here, we demonstrate...
Abstract Superconductivity in the vicinity of a competing electronic order often manifests itself with superconducting dome, centered at presumed quantum critical point phase diagram. This common feature, found many unconventional superconductors, has supported prevalent scenario which fluctuations or partial melting parent are essential for inducing enhancing superconductivity. Here we present contrary example, IrTe 2 nanoflakes dome is identified well inside stripe charge ordering...
Due to the critical importance of carbon neutrality for survival humanity, passive thermal management, which manages energy without additional consumption, has become increasingly attractive. Camouflage materials offer a promising solution as they can dissipate heat through radiation, reducing need energy-intensive cooling systems. However, developing effective infrared (IR) camouflage solutions low-temperature environments and small-sized applications remains challenge because low...
Transformers have achieved great success in effectively processing sequential data such as text. Their architecture consisting of several attention and feedforward blocks can model relations between elements a sequence parallel manner, which makes them very efficient to train effective modeling. Even though they shown strong performance data, the size their parameters is considerably larger when compared other architectures RNN CNN based models. Therefore, approaches explored parameter...
We investigated phase defects in a quasi-one-dimensional commensurate charge density wave (CDW) system, an In atomic wire array on Si(111), using low temperature scanning tunneling microscopy. The unique four-fold degeneracy of the CDW state leads to various defects, among which intrinsic solitons are clearly distinguished. exhibit characteristic variation amplitude with coherence length about 4 nm, as expected from electronic structure, and localized within gap. While most observed trapped...
We describe the development and capabilities of an advanced system for nanoscale electrical transport studies. This consists a low temperature four-probe scanning tunneling microscope (STM) high-resolution electron coupled to molecular-beam epitaxy sample preparation chamber. The four STM probes can be manipulated independently with subnanometer precision, enabling atomic resolution imaging four-point study surface electronic systems nanostructured materials at temperatures down 10K....
The complex interplay between the electron and lattice degrees of freedom produces multiple nearly degenerate electronic states in correlated materials. competition these largely determines functionalities system, but invoked mechanism remains debate. By imaging phase domains with microscopy interrogating individual situ via transport spectroscopy double-layered Sr(3)(Ru(1-x)Mn(x))(2)O(7) (x = 0 0.2), we show real-space that microscopic Mott-type metal-insulator transition are extremely...
Atomic-scale exchange between two different cations of similar size in crystalline oxides is one the major types point defects when multiple oxygen interstitials are arrayed an ordered manner. Although a number studies have been performed on variety Li-intercalation olivine phosphates to determine distribution bulk, understanding thermodynamic stability subsurface regions and its dependency crystallographic orientation at surface has remained elusive. Through combination small-angle neutron...