Results for "Siheon Ryee"

total 13took 0.03s
Magnetic ground state of SrRuO$_3$ thin film and applicability of standard first-principles approximations to metallic magnetismFeb 28 2017Jun 21 2017A systematic first-principles study has been performed to understand the magnetism of thin film SrRuO$_3$ which lots of research efforts have been devoted to but no clear consensus has been reached about its ground state properties. The relative t$_{2g}$ ... More
Comparative study of DFT+$U$ functionals for non-collinear magnetismFeb 27 2018Jun 11 2018We performed comparative analysis for DFT+$U$ functionals to better understand their applicability to non-collinear magnetism. Taking LiNiPO$_4$ and Sr$_2$IrO$_4$ as examples, we investigated the results out of two formalisms based on charge-only density ... More
The effect of double counting, spin density, and Hund interaction in the different DFT+$U$ functionalsSep 11 2017Jun 20 2018A systematic comparative study has been performed to better understand DFT$+U$ (density functional theory + $U$) method. We examine the effect of choosing different double counting and exchange-correlation functionals. The calculated energy distribution ... More
Charge density functional plus $U$ theory of LaMnO$_3$: Phase diagram, electronic structure, and magnetic interactionMar 01 2018We perform charge density functional theory plus $U$ calculation of LaMnO$_3$. While all the previous calculations were based on spin density functionals, our result and analysis show that the use of spin-unpolarized charge-only density is crucial to ... More
Sub-room temperature ferromagnetism and its nature in VSe$_2$ monolayerJul 10 2019Magnetic van der Waals materials provide an ideal platform for exploring two-dimensional magnetism of technological and scientific importance. Among them, 1T-VSe$_2$ has been reported as one of the first room-temperature two-dimensional ferromagnets. ... More
Quantified Degeneracy, Entropy and Metal-Insulator Transition in Complex Transition-Metal OxidesOct 01 2018Understanding complex correlated oxides and their phase transitions has long been a challenge. The difficulty largely arises from the intriguing interplay between multiple degrees of freedoms. While degeneracy can play an important role in determining ... More
Microscopic understanding of magnetic interactions in bilayer CrI$_3$Sep 05 2018We performed the detailed microscopic analysis of the inter-layer magnetic couplings for bilayer CrI$_3$. As the first step toward understanding the recent experimental observations and utilizing them for device applications, we estimated magnetic force ... More
Microscopic understanding of magnetic interactions in bilayer CrI$_3$Sep 05 2018Apr 02 2019We performed the detailed microscopic analysis of the inter-layer magnetic couplings for bilayer CrI$_3$. As the first step toward understanding the recent experimental observations and utilizing them for device applications, we estimated magnetic force ... More
Charge density functional plus $U$ calculation of lacunar spinel GaM$_4$Se$_8$ (M = Nb, Mo, Ta, and W)Jan 03 2019Charge density functional plus $U$ calculations are carried out to examine the validity of molecular $J_\text{eff}$=1/2 and 3/2 state in lacunar spinel GaM$_4$X$_8$ (M = Nb, Mo, Ta, and W). With LDA (spin-unpolarized local density approximation)$+U$, ... More
On the origin and the manipulation of ferromagnetism in Fe$_3$GeTe$_2$: defects and dopingsApr 09 2019To understand the magnetic properties of Fe$_3$GeTe$_2$, we performed the detailed first-principles study. Contrary to the conventional wisdom, it is unambiguously shown that Fe$_3$GeTe$_2$ is not ferromagnetic but antiferromagnetic carrying zero net ... More
Microscopic understanding of magnetic interactions in bilayer CrI$_3$Sep 05 2018Apr 09 2019We performed the detailed microscopic analysis of the inter-layer magnetic couplings for bilayer CrI$_3$. As the first step toward understanding the recent experimental observations and utilizing them for device applications, we estimated magnetic force ... More
Quasiparticle self-consistent GW calculation of Sr$_2$RuO$_4$ and SrRuO$_3$:Jul 31 2015Jan 25 2016Using quasiparticle self-consistent $GW$ calculations, we re-examined the electronic structure of Sr$_2$RuO$_4$ and SrRuO$_3$. Our calculations show that the correlation effects beyond the conventional LDA (local density approximation) and GGA (generalized ... More
Enhanced metallic properties of SrRuO3 thin films via kinetically controlled pulsed laser epitaxyOct 20 2016Metal electrodes are a universal element of all electronic devices. Conducting SrRuO3 (SRO) epitaxial thin films have been extensively used as electrodes in complex-oxide heterostructures due to good lattice mismatches with perovskite substrates. However, ... More