Yong Kwon Kim

High-temperature superconductivity in cuprates arises from an electronic state that remains poorly understood. We report the observation of a related electronic state in a noncuprate material, strontium iridate (Sr2IrO4), in which the distinct cuprate fermiology is largely reproduced. Upon surface electron doping through in situ deposition of alkali-metal atoms, angle-resolved photoemission spectra of Sr2IrO4 display disconnected segments of zero-energy states, known as Fermi arcs, and a gap as

A superconducting transition temperature (Tc) as high as 100 K was recently discovered in one monolayer FeSe grown on SrTiO3. The discovery ignited efforts to identify the mechanism for the markedly enhanced Tc from its bulk value of 8 K. There are two main views about the origin of the Tc enhancement: interfacial effects and/or excess electrons with strong electron correlation. Here, we report the observation of superconductivity below 20 K in surface electron-doped bulk FeSe. The doped surface

Three plastic scintillators of 4.5 cm diameter and 2.5-cm length were fabricated for comparison with commercial plastic scintillators using polymerization of the styrene monomer 2.5-diphenyloxazole (PPO) and 1,4-bis benzene (POPOP). Their maximum emission wavelengths were determined at 426.06 nm, 426.06 nm, and 425.00 nm with a standard error of 0.2% using a Varian spectrophotometer (Agilent, Santa Clara, CA, USA). Compton edge spectra were measured using three gamma ray sources [i.e., cesium 13

We present a new composite material composed of pH sensitive fluorescent dyes in a poly(<italic>N</italic>-isopropylacrylamide)-based hydrogel and incorporating glucose oxidase (GOx), which provides a platform for fluorescence sensing of glucose.

New emission color-changeable hydrogels containing glucose oxidase were synthesized to be used in glucose sensing.

Abstract A very simple polydimethylsiloxane (PDMS) pattern‐transfer method is devised, called buffered‐oxide etchant (BOE) printing. The mechanism of pattern transfer is investigated, by considering the strong adhesion between the BOE‐treated PDMS and the SiO 2 substrate. PDMS patterns from a few micrometers to sub‐micrometer size are transferred to the SiO 2 substrate by just pressing a stamp that has been immersed in BOE solution for a few minutes. The patterned PDMS layers work as perfect phy

Fast neutron applications have gained popularity with the growth of fast neutron production facilities. Covering a larger area and/or wider angle can be one of the advantages of a fast neutron detector. In the present study, a large-area composite stilbene scintillator with the dimensions of 200 mm (D) × 20 mm (H) was fabricated to examine its scintillation properties and to evaluate its applicability to fast neutron detection. The detector response of small- and large-area composite stilbene sc

A ZnSe crystal based on a II -VI compound semiconductor has various physical properties: electroluminescent, photoelectric, luminescent and scintillation. Activated ZnSe crystals are highly-efficient scintillators, and they are already being applied to the detecting units of a X-ray introscopy and a dosimetric system. ZnSe-based scintillators have a high absolute light output, and their radiation spectra matches well with the Si-photodiode spectral sensitivity.The present study was performed by