Light and Matter Theory
Laboratory
Welcome to
Theoretical studies on materials
Theoretical study based on quantum physics is a way to understand properties of emergent materials. We use computational methods performed on model calculation and first-principle density functional theory to study new physics of the materials.
Main frameworks of our study
Semiconducting, magnetic, relativistic properties of emergent materials.
Ultrafast time-resolved study of non-equilibrium phenomena.
Advanced functional nano applications and their physical principles.
News
A WORK OF DEPHASING IN HIGH HARMONIC GENERATIONS HAS BEEN ACCEPTED IN NANO LETTERS
"Dephasing dynamics accessed by high harmonic generation: determination of electron-hole decoherence of Dirac fermions"
Youngjae Kim, Min Jeong Kim, Soonyoung Cha, Shinyoung Choi, Cheol-Joo Kim, B. J. Kim, Moon-Ho Jo, Jonghwan Kim*, J. D. Lee*
Nano Letters 24, 4, 1277–1283, (2024).
A WORK OF BERRY CURVATURE IN THE PHOTOEMISSION DELAY HAS BEEN AWARDED AT ATTO9 CONFERENCE
"Berry curvature in the photoelectron emission delay"
Hyosub Park, and J. D. Lee*
9th International Conference on Attosecond Science and Technology (July 9-14, 2023)
A WORK OF PHONON INDUCED PSEUDOSPIN ROTATION HAS BEEN ACCEPTED IN CARBON. (IF=11.307)
"Phonon induced pseudospin rotation in graphene"
Jiwon Jeon, Youngjae Kim, and J. D. Lee*
Carbon 201, 425-432 (2023).
A WORK OF QUANTUM PATHWAY OF HIGH HARMONIC GENERATION HAS BEEN ACCEPTED IN NAT. COMM.
"Gate-tunable quantum pathways of high harmonic generation in graphene"
Soonyoung Cha, Minjeong Kim, Youngjae Kim, Shinyoung Choi, Sejong Kang, Hoon Kim, Gil Young Cho, Moon Jeong Park, Cheol-Joo Kim, B. J. Kim, JaeDong Lee*, Moon Ho Jo*, and Jonghwan Kim*
Nat. Comm. 13, 6630 (2022).
About Our Research
◇ Emerging materials and their hybrids ◇
The strong molybdenum-bismuth band hybridization together with a generation of the interfacial
dipole field induces the giant Rashba-type splitting accompanying the proper spin topology
in molybdenum-driven bands at the Γ point.
We investigate the strain-induced electronic and magnetic properties of single-layer (1L) MoS2 with
vacancy defects using the density functional theory calculation. When the tensile strain is applied,
1L-MoS2 with vacancy becomes ferromagnetic and metallic.
Optical absorption spectra of AMoS2NRs show the exciton multibands (their binding energies are close to or
less than 1 eV) which are much stronger than a single layer of MoS2. However, they are absent in the spectra
by the approach of GW and the random phase approximation (RPA). This signifies that the excitonic correlation
effects are strongly enhanced in the reduced dimensional structure of MoS2.
External electric field driven renormalized velocity of spin filtered-massless Dirac fermions in functionalized
GaBi giant topological insulator.
◇ Extreme ultrafast phenomena ◇
An asymmetric conducting of the current by forming a heterojunction made of two distinct dielectrics with
a low hole mass (mh≪me) and low electron mass (me≪mh), respectively. This proposition introduces the
novel concept of a petahertz (1015 Hz) diode to rectify the current in the petahertz domain.
Higher-order Fano resonances in attosecond resonant photoemission of copper dichloride.
Bottom left: Phase difference etween photoelectron and Auger electron. Right: Higher-order
Fano resonance bands.
Ultrafast above-transition-temperature resurrection of spin density wave driven in BaFe2As2. Under the
ultrafast optical pumping, a pronounced spin–phonon coupling is found to drive the reconstruction of spin
density wave (SDW) through the coherent phonon generation.