Welcome to
Theoretical studies on quantum dynamics & information
Quantum dynamics enables us to explore fundamental properties of materials and quantum information theory. We theoretically investigate these quantum dynamics and information with model calculation and first-principle density functional theory.
Main frameworks of our study
Coherence, Entanglement, and Quantum information
Ultrafast dynamics and non-equilibrium properties of materials
Semiconducting materials, low-dimensional materials, and strongly-correlated systems
Advanced functional nano applications and their physical principles.
News
A WORK OF NOVEL QUANTUM STATES OF EXCITON-FLOQUET COMPOSITES HAS BEEN ACCEPTED IN NANO LETTERS
"Novel quantum states of exciton-Floquet composites: electron-hole entanglement and information"
Hyosub Park, Noejung Park, and J. D. Lee*
Nano Letters 42, 13192-13199 (2024).
A WORK OF BERRY CURVATURE IN THE PHOTOELECTRON EMISSION DELAY HAS BEEN ACCEPTED IN NPJ COMPUT. MATER.
A WORK OF DEPHASING IN HIGH HARMONIC GENERATIONS HAS BEEN ACCEPTED IN NANO LETTERS
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)
A WORK OF QUANTUM PATHWAY OF HIGH HARMONIC GENERATION HAS BEEN ACCEPTED IN NAT. COMM.
About Our Research
◇ Ultrafast Dynamics and Quantum information ◇
The interplay between exciton and Floquet states in 2D materials is investigated by time- and angle-resolved photoemission spectroscopy and quantum entanglement. It is found that the interplay forms a temporal novel quantum state, exciton-Floquet composites.
Investigation of attosecond photoelectron emission delay in 2D materials. It is found that the coherent mixing of valence and conduction generated by the optical driving induces a novel attosecond photoemission delay, which contains the Berry curvature signature of the system.
npj Comput. Mater. 10, 174 (2024)
Under electron-phonon interaction Hamiltonian describing a change of the pseudospin direction in a sense of the quantum mechanical rotation (SU(2) rotation), dichroic photoemission of an electron in graphene is studied. Nonvanishing Berry curvatures originated from broken time-reversal symmetry caused by emitted elliptic phonon in the rotation process are detected with time-resolved photoemission spectroscopy.
We investigate HHG and its circular dichroism in undoped monolayer MoS2 with a strain and bias field.
The dichroism of HHG captures the nonzero net Berry curvature of the monolayer MoS2.
Phys. Rev. B 106, 205422 (2022)
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 between 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.