김용관 교수

We performed angle-resolved photoelectron spectroscopy (ARPES) studies on mechanically detwinned BaFe${}_{2}$${\mathrm{As}}_{2}$. We observe clear band dispersions, and the shapes and characters of the Fermi surfaces are identified. Shapes of two-hole pockets around the $\ensuremath{\Gamma}$ point are found to be consistent with the Fermi surface topology predicted in the orbital ordered states. Dirac-cone-like band dispersions near the $\ensuremath{\Gamma}$ point are clearly identified as theor

Diffuser fouling is classified as one of three types, A, B, and C, based on the nature of the foulant. The accumulation of inorganic foulants, such as fine particles and precipitates, characterize type A fouling, and the formation of biomass‐characterize type B fouling. Type C fouling is characterized by the formation of biofilm, fortified by the entrapment of inorganic particles within the biomass. Hypotheses were developed to describe the mechanisms of dynamic change in diffuser operating perf

Abstract Topological quantum phases are largely understood in weakly correlated systems, which have identified various quantum phenomena, such as the spin Hall effect, protected transport of helical fermions, and topological superconductivity. Robust ferromagnetic order in correlated topological materials particularly attracts attention, as it can provide a versatile platform for novel quantum devices. Here, a singular Hall response arising from a unique band structure of flat topological nodal

This article presents the experimental work for the treatment of landfill leachate in a combined process using the white rot fungus Phanerochaete chrysosporium and the natural zeolite Clinoptilolite. Clinoptilolite was used in a pretreatment step as a sink for ammonia nitrogen and, on average it reduced the levels of ammonia nitrogen, soluble chemical oxygen demand (COD) and color by 72, 4.7, and 25%, respectively. The reductions by fungal treatment alone were 16.6, 21.5, and 31.2%, respectively

We report the synthesis of ethylenediamine-intercalated NbSe 2 and Li-ethylenediamine-intercalated MoSe 2 single crystals with increased interlayer distances and their electronic structures measured by means of angle-resolved photoemission spectroscopy (ARPES). X-ray diffraction patterns and transmission electron microscopy images confirm the successful intercalation and an increase in the interlayer distance. ARPES measurement reveals that intercalated NbSe 2 shows an electronic structure almos

The technical evolution of angle-resolved photoemission spectroscopy (ARPES) in the late 90s played a pivotal role in the exploration of electronic structures in condensed matter systems. ARPES achieved numerous successes during this period, notably capturing the first evidence of the unconventional d-wave symmetry of the superconducting gap in cuprate superconductors. It also elucidated the essential rules governing topological signatures in the electronic structures of topological materials, a

Three different bioassays for analysis of biodegradable dissolved organic carbon (BDOC) were evaluated to identify which method is most applicable to analysis of drinking water. The determination of BDOC is primarily based on the differences between initial and final DOC levels during a certain incubation period using indigenous bacterial consortium as an inoculum. The assay procedures basically differ in the preparation method of inoculum. Inoculum was added in the form of suspended bacteria in

Abstract Two-dimensional electrides can acquire topologically non-trivial phases due to intriguing interplay between the cationic atomic layers and anionic electron layers. However, experimental evidence of topological surface states has yet to be verified. Here, via angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM), we probe the magnetic Weyl states of the ferromagnetic electride [Gd 2 C] 2+ ·2e − . In particular, the presence of Weyl cones and Fermi-arc

In 2D noble metals like copper, the carrier scattering at grain boundaries has obscured the intrinsic nature of electronic transport. However, it is demonstrated that the intrinsic nature of transport by hole carriers in 2D copper can be revealed by growing thin films without grain boundaries. As even a slight deviation from the twin boundary is perceived as grain boundaries by electrons, it is only through the thorough elimination of grain boundaries that the hidden hole-like attribute of 2D si

Rashba states have been actively revisited as a platform for advanced applications such as spintronics and topological quantum computation. Yet, access to the Rashba state is restricted to the specific material sets, and the methodology to control the Rashba state is not established. Here, we report the Rashba states on the (001) surface of KZnBi, a 3D Dirac semimetal. Using angle-resolved photoemission spectroscopy and first-principles calculations, we investigated the evolution of Rashba state

∼150 K. Using angle-resolved photoemission spectroscopy, we identify that a fully isotropic gap opens selectively on one of the Fermi surfaces with finite warping along the interlayer direction. This band selectivity is incompatible with conventional gap opening mechanisms associated with symmetry breaking. These findings, together with the unusual field-dependent magnetoresistance, suggest that the Kondo-type proximity coupling of itinerant Fe electrons to localized V spin plays a role in stabi