http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The electronic correlations in graphene standing on SrTiO₃ and platinum substrates
Jinwoong Hwang,Hyejin Ryu,Hwihyeon Hwang,Min-Jeong Kim,Ji-Eun Lee,Qin Zhou,Debin Wang,Ankit S. Disa,Jonathan Denlinger,Yuegang Zhang,Alessandra Lanzara,Sung-Kwan Mo,Choongyu Hwang 한국진공학회 2018 한국진공학회 학술발표회초록집 Vol.2018 No.2
Gapped Nearly Free-Standing Graphene on an SiC(0001) Substrate Induced by Manganese Atoms
Hwang, Jinwoong,Lee, Ji-Eun,Kang, Minhee,Park, Byeong-Gyu,Denlinger, Jonathan,Mo, Sung-Kwan,Hwang, Choongyu The Korean Vacuum Society 2018 Applied Science and Convergence Technology Vol.27 No.5
The electron band structure of manganese-adsorbed graphene on an SiC(0001) substrate has been studied using angle-resolved photoemission spectroscopy. Upon introducing manganese atoms, the conduction band of graphene, that is observed in pristine graphene indicating intrinsic electron-doping by the substrate, completely disappears and the valence band maximum is observed at 0.4 eV below Fermi energy. At the same time, the slope of the valence band decreases by the presence of manganese atoms, approaching the electron band structure calculated using the local density approximation method. The former provides experimental evidence of the formation of nearly free-standing graphene on an SiC substrate, concomitant with a metal-to-insulator transition. The latter suggests that its electronic correlations are efficiently screened, suggesting that the dielectric property of the substrate is modified by manganese atoms and indicating that electronic correlations in grpahene can also be tuned by foreign atoms. These results pave the way for promising device application using graphene that is semiconducting and charge neutral.
Emergence of Kondo Resonance in Graphene Intercalated with Cerium
Hwang, Jinwoong,Kim, Kyoo,Ryu, Hyejin,Kim, Jingul,Lee, Ji-Eun,Kim, Sooran,Kang, Minhee,Park, Byeong-Gyu,Lanzara, Alessandra,Chung, Jinwook,Mo, Sung-Kwan,Denlinger, Jonathan,Min, Byung Il,Hwang, Choong American Chemical Society 2018 NANO LETTERS Vol.18 No.6
<P>The interaction between a magnetic impurity, such as cerium (Ce) atom, and surrounding electrons has been one of the core problems in understanding many-body interaction in solid and its relation to magnetism. Kondo effect, the formation of a new resonant ground state with quenched magnetic moment, provides a general framework to describe many-body interaction in the presence of magnetic impurity. In this Letter, a combined study of angle-resolved photoemission (ARPES) and dynamic mean-field theory (DMFT) on Ce-intercalated graphene shows that Ce-induced localized states near Fermi energy, <I>E</I><SUB>F</SUB>, hybridized with the graphene π-band, exhibit gradual increase in spectral weight upon decreasing temperature. The observed temperature dependence follows the expectations from the Kondo picture in the weak coupling limit. Our results provide a novel insight how Kondo physics emerges in the sea of two-dimensional Dirac electrons.</P> [FIG OMISSION]</BR>
Bok, Jinwoong,Zenczak, Colleen,Hwang, Chan Ho,Wu, Doris K. National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.34
<P>Neural precursor cells of the central nervous system undergo successive temporal waves of terminal division, each of which is soon followed by the onset of cell differentiation. The organ of Corti in the mammalian cochlea develops differently, such that precursors at the apex are the first to exit from the cell cycle but the last to begin differentiating as mechanosensory hair cells. Using a tissue-specific knockout approach in mice, we show that this unique temporal pattern of sensory cell development requires that the adjacent auditory (spiral) ganglion serve as a source of the signaling molecule Sonic hedgehog (Shh). In the absence of this signaling, the cochlear duct is shortened, sensory hair cell precursors exit from the cell cycle prematurely, and hair cell differentiation closely follows cell cycle exit in a similar apical-to-basal direction. The dynamic relationship between the restriction of <I>Shh</I> expression in the developing spiral ganglion and its proximity to regions of the growing cochlear duct dictates the timing of terminal mitosis of hair cell precursors and their subsequent differentiation.</P>
박진웅 ( Jinwoong Park ),문지훈 ( Jihoon Moon ),김용성 ( Yongsung Kim ),황인준 ( Eenjun Hwang ) 한국정보처리학회 2016 한국정보처리학회 학술대회논문집 Vol.23 No.1
최근 에너지 효율을 최적화하는 차세대 지능형 전력망인 스마트 그리드 시스템(Smart Grid System)이 국내외에 널리 보급되고 있다. 그로 인해 그리드 시스템의 효율적인 운영을 위해 적용되는 EMS(Energy Management System) 기술의 중요성이 커지고 있다. EMS는 에너지 사용량 예측의 높은 정확성이 요구되며, 예측이 정확하게 수행될수록 에너지의 활용성이 높아진다. 본 논문은 전력 사용량 예측의 정확성 향상을 위한 새로운 기법을 제안한다. 구체적으로, 먼저 사용량에 영향을 미치는 환경적인 요인들을 분석한다. 분석된 요인들을 적용하여 유사한 환경을 가지는 전력 사용량 데이터의 사전 군집화를 수행한다. 그리고 예측 일에 관련된 환경 정보와 가장 유사한 군집의 전력 사용량 데이터를 기반으로 전력 사용량을 예측한다. 제안하는 기법의 성능을 평가하기 위해, 다양한 실험을 통하여 일간 전력 사용량을 예측하고 그 정확성을 측정하였다. 결과적으로, 기존의 기법들과 비교했을 때, 최대 52.88% 향상된 전력 사용량 예측 정확성을 보였다.
Kang, Minhee,Hwang, Jinwoong,Lee, Ji-Eun,Fedorov, Alexei,Hwang, Choongyu Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.467 No.-
<P><B>Abstract</B></P> <P>The interplay between electron-electron interaction and electron-phonon coupling has been one of the key issues in graphene as it can provide information on the origin of enhanced electron-phonon coupling in graphene by foreign atoms. In ytterbium-decorated graphene on SiC substrate, electron-phonon coupling exhibits strong enhancement compared to that of as-grown graphene. Based on angle-resolved photoemission study, the presence of ytterbium is also found to result in the decrease of Fermi velocity, revealing the enhancement of electron-electron interaction within the Fermi liquid theory. Our finding on the concomitant enhancement of electron-electron interaction and electron-phonon coupling suggests a possibility of the interplay between the two representative many-body interactions in graphene decorated with foreign atoms.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ytterbium-decorated graphene shows enhanced electron-phonon (el-ph) coupling. </LI> <LI> Ytterbium also leads to the enhancement of electron-electron (el-el) interaction in graphene. </LI> <LI> The concomitant enhancement indicates an interplay between el-el and el-ph interations. </LI> <LI> This result suggests a plausible route towards the realization of superconducting graphene. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>