A5078221830- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Luminescence Properties of Advanced Materials
- Radiation Detection and Scintillator Technologies
- Molecular Junctions and Nanostructures
- Ferroelectric and Piezoelectric Materials
- Glass properties and applications
- Multiferroics and related materials
- Solid State Laser Technologies
- Organic Light-Emitting Diodes Research
- Semiconductor materials and devices
- Organic Electronics and Photovoltaics
- Magnetic and transport properties of perovskites and related materials
- Astrophysics and Cosmic Phenomena
- Physics of Superconductivity and Magnetism
- Photocathodes and Microchannel Plates
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Semiconductor Quantum Structures and Devices
- Lanthanide and Transition Metal Complexes
- Neutrino Physics Research
- ZnO doping and properties
- Nuclear Physics and Applications
Institute for Basic Science
2004-2024
Fermi National Accelerator Laboratory
2015-2021
University of Seoul
2017
The University of Texas at Arlington
2009-2015
Northwestern University
2015
Changwon National University
2001-2013
The University of Texas at Austin
2013
Korea Atomic Energy Research Institute
2011
Rutgers, The State University of New Jersey
2004-2007
Chemnitz University of Technology
1999-2002
The Center for Axion and Precision Physics Research at the Institute Basic Science is searching axion dark matter using ultralow temperature microwave resonators. We report exclusion of mass range $10.7126--10.7186\text{ }\text{ }\ensuremath{\mu}\mathrm{eV}$ with near Kim-Shifman-Vainshtein-Zakharov (KSVZ) coupling sensitivity $10.16--11.37\text{ about 9 times larger 90% confidence level. This first search result in these ranges. It also a resonator physical less than 40 mK.
We have studied the magnetostructural phase diagram of multiferroic TbMn2O5 as a function temperature and magnetic field by neutron diffraction. Dielectric anomalies are found to be associated with steps in propagation vector, including rare example commensurate-incommensurate transition on cooling below 24 K, structural parameters. The geometrically frustrated structure is stabilized "canted antiferroelectric" displacements Mn3+ ions, an Jahn-Teller effect. Tb moments order...
We have studied the crystal and magnetic structures of magnetoelectric materials $R{\mathrm{Mn}}_{2}{\mathrm{O}}_{5}$ $(R=\mathrm{Tb},\mathrm{Ho},\mathrm{Dy})$ using neutron diffraction as a function temperature. All three display incommensurate antiferromagnetic ordering below $40\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, becoming commensurate on further cooling. For $R=\mathrm{Tb},\mathrm{Ho}$, commensurate-incommensurate transition takes place at low temperatures. The been solved are...
The commensurate and incommensurate magnetic structures of the magnetoelectric system ${\mathrm{YMn}}_{2}{\mathrm{O}}_{5}$, as determined from neutron diffraction, were found to be spin-density waves lacking a global center symmetry. We propose model, based on simple magnetoelastic coupling lattice, which enables us predict polarization entirely observed structure. Our data accurately reproduce temperature dependence spontaneous polarization, particularly its sign reversal at...
A Raman spectroscopic study of the high-frequency optical phonons in single crystals multiferroic system $R{\mathrm{Mn}}_{2}{\mathrm{O}}_{5}$ ($R=\mathrm{Bi}$, Eu, Dy) was performed. All studied materials show anomalous phonon shifts, below a new characteristic temperature for these materials, ${T}^{*}\ensuremath{\sim}60--65\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The sign and magnitude such shifts appear to be correlated with ionic radius $R$, envolving from softenings $R=\mathrm{Bi}$...
We propose using the storage ring electric dipole moment (EDM) method to search for axion dark matter induced EDM oscillation in nucleons. The uses a combination of $B$ and $E$ fields produce resonance between $g\ensuremath{-}2$ spin precession frequency background field greatly enhance sensitivity it. An range from ${10}^{\ensuremath{-}9}\text{ }\text{ }\mathrm{Hz}$ 100 MHz can, principle, be scanned with high sensitivity, corresponding an ${f}_{a}$ $1{0}^{13}\text{...
Based on the notion that local dark-matter field of axions or axionlike particles (ALPs) in our Galaxy induces oscillating couplings to spins nucleons and nuclei (via electric dipole moment latter and/or paramagnetic axion-wind effect), we establish feasibility a new method search for ALPs storage rings. previous work allows us maintain in-plane polarization stored deuteron beam few hundred seconds, perform first proof-of-principle experiment at Cooler Synchrotron (COSY) scan momenta near...
We present Raman studies of the vibrational properties 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) single crystals. Davydov splitting internal molecular vibrations due to interaction two molecules in a unit cell was observed. Features PTCDA crystal lattice low-frequency region spectra are reported. films deposited on passivated Si and GaAs surfaces also reveal specific features crystalline structure: appearance phonon lines spectra.
The axion, a consequence of the PQ mechanism, has been considered as most elegant solution to strong-CP problem and compelling candidate for cold dark matter. Center Axion Precision Physics Research (CAPP) Institute Basic Science (IBS) was established on 16 October 2013 with main objective launch state art axion experiments in South Korea. Relying haloscope technique, our strategy is run several parallel explore wide range masses sensitivities better than QCD models. We utilize not only...
Abstract The Center for Axion and Precision Physics Research at the Institute Basic Science in Republic of Korea is home to multiple active axion search experiments using cavity haloscopes that operate within frequency range 1–6 GHz. convert axions photons, resulting an output power about 10 $${^{-24}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>24</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:math> –10...
The axion is a hypothetical particle, promising candidate for dark matter, and solution to the strong CP problem.Axion haloscope search experiments deal with signal power comparable noise uncertainty at millikelvin temperature.We use flux-driven Josephson parametric amplifier (JPA) aim of approaching level near theoretically allowed limit half quanta.In our measurements characterize JPA we have found added system as first-stage be lower than 110 mK frequencies from 0.938 GHz 0.963 GHz.
A temperature dependent Raman scattering study in multiferroic single crystals RMn2O5 (R=Bi, Eu, and Dy) was performed. The spectra were measured the range from 150to450cm−1 involving mostly Mn–O–Mn bending vibrations, complementing our previous work a higher frequency Mn–O stretching modes. number of studied phonons present anomalous behavior below characteristic temperature, T*∼60–65K, such as that found for sign magnitude appear to be correlated with ionic radius R, being softening R=Bi...
We prepared two kinds of Sm-doped strontium borates. When the samples were in air environment, while Sm3+ ions doped tetraborate (STB) well reduced, trivalent Sm partially reduced hexaborate (SHB). The SHB was successfully by subsequent x-ray irradiation (SHBX) and showed a strong Sm2+ emission. photoluminescence, excitation spectrum spectral hole burning experiments conducted for samples. crystallographic sites found to be different STB SHBX. Spectral holes observed at room temperature both...
The optical properties of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) films grown by organic molecular beam deposition (OMBD) on passivated Si and GaAs substrates were determined using variable angle spectroscopic ellipsometry (VASE) reflectance anisotropy spectroscopy (RAS). All PTCDA layers deposited at room temperature with a low rate about 0.2 nm/min are strongly optically anisotropic treated as uniaxial. From the VASE measurements in-plane refractive indices extinction...
The initial stage of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) adsorption on Se-passivated n-type GaAs(100)-(2×1) surface was investigated using high-resolution soft x-ray photoemission spectroscopy. A very small amount PTCDA (≪1 ML) is sufficient to induce a reduction inhomogeneous band bending at the as judged from sharpening core level spectra. This interpreted in terms preferential sticking organic molecules defects. results presented this letter indicate that may also serve...