A5049947688- Graphene research and applications
- 2D Materials and Applications
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Topological Materials and Phenomena
- Gyrotron and Vacuum Electronics Research
- MXene and MAX Phase Materials
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Thermal properties of materials
- Electronic and Structural Properties of Oxides
- Spacecraft and Cryogenic Technologies
- Diamond and Carbon-based Materials Research
- Advanced Thermoelectric Materials and Devices
- Perovskite Materials and Applications
- Boron and Carbon Nanomaterials Research
- Advanced X-ray Imaging Techniques
Yonsei University
2017-2023
Pohang University of Science and Technology
2001-2021
Institute for Basic Science
2015
Pohang Accelerator Laboratory
2001
Black phosphorus consists of stacked layers phosphorene, a two-dimensional semiconductor with promising device characteristics. We report the realization widely tunable bandgap in few-layer black doped potassium using an in-situ surface doping technique. Through band-structure measurements and calculations, we demonstrate that vertical electric field from dopants modulates owing to giant Stark effect tunes material moderate-gap band-inverted semimetal. At critical this band inversion,...
We report the realization of novel symmetry-protected Dirac fermions in a surface-doped two-dimensional (2D) semiconductor, black phosphorus. The widely tunable band gap phosphorus by surface Stark effect is employed to achieve surprisingly large inversion up ∼0.6 eV. High-resolution angle-resolved photoemission spectra directly reveal pair creation points and their movement along axis glide-mirror symmetry. Unlike graphene, point stable, as protected space-time symmetry, even presence...
Abstract A variety of phase transitions have been found in two-dimensional layered materials, but some their atomic-scale mechanisms are hard to clearly understand. Here, we report the discovery a transition whose mechanism is identified as interlayer sliding lead iodides, material widely used synthesize halide perovskites. The low-temperature crystal structure iodides not 2H polytype known before, non-centrosymmetric 4H polytype. This undergoes order-disorder characterized by abrupt...
Abstract A widely tunable band gap in few‐layer K‐doped black phosphorus is realized by situ deposition of potassium atoms.
Pohang Accelerator Laboratory has prepared to SRF 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> harmonic cavity increase beam lifetime and damp orbit instability by lengthening electron bunch in PLS. The was developed its vertical test done already with success. Higher order modes were analyzed optimize performance orbit. Most of them are not effective beam, while the others have possibility impact stability. These harmful HOMs can...
Pohang Accelerator Laboratory, POSTECH have studied SRF cavity and constructed test laboratory from January 2006. The first activity for research was to develop 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> harmonic PLS, which done in 2006 the cryostat are under design. fabrication of ICHIRO cavity, is ILC ACD PAL's second related SRF. Deep drawing, trimming welding by electron beam a 9-cell were PAL. polishing processes RF surface...
The physical engineering design of a 7.5 Tesla superconducting wiggler for the PLS is described. based on three parallel dipoles. field produced by six racetrack NbTi-coils assembled symmetrically above and below vacuum chamber. current density central pole was chosen to obtain optimal field-current characteristics within conductor packages. use iron poles return yokes makes it possible produce higher fields than corresponding values when no used.< <ETX...