Moon-Joo Lee
Pohang University of Science and Technology · 物理学・天文学
研究室紹介
Professor Moon-Joo Lee's research lab specializes in quantum optics, integrated quantum photonics, and trapped-ion quantum systems. The lab focuses on developing miniaturized, high-fidelity quantum interfaces using on-chip photonic structures and microelectromechanical systems (MEMS), with applications in scalable quantum networks. Key research directions include nondestructive quantum state measurement, exceptional point physics in cavity-QED systems, and advanced laser stabilization techniques for ultracold atoms and trapped ions. The lab combines theoretical design with experimental implementation, emphasizing compact, robust, and scalable quantum devices.
Research Overview
Research Output Trend
Figures are computed from collected data and may differ slightly.
Selected Papers
15The objective of this study was to determine the effect of electron-beam irradiation on the oxidation of cholesterol in raw and cooked chicken meats with different packaging and storage times. Patties were prepared with skinless chicken breasts and legs. Half of the patties were used for raw meat study and the other half for cooked meat work. For cooked samples, patties were cooked in an electric oven to an internal temperature of 70 C. Raw and cooked meat patties were either aerobically or vacu
This paper describes the inverse design of the particle swarm optimization algorithm combined with the three-dimensional finite-difference time-domain simulation to design a waveguide crossing that resembles a binary code. The device consists of 15 × 15 air holes in a 220-nm silicon slab on a 3-μm-thick SiO2 substrate with one input port and three output waveguide ports. The designed device has a small footprint of 4μm2 and a short simulation time of 1.7 h. In the wavelength range of 1.5–1.6μm,
We dispersively couple a single trapped ion to an optical cavity to extract information about the cavity photon-number distribution in a nondestructive way. The photon-number-dependent ac Stark shift experienced by the ion is measured via Ramsey spectroscopy. We use these measurements first to obtain the ion-cavity interaction strength. Next, we reconstruct the cavity photon-number distribution for coherent states and for a state with mixed thermal-coherent statistics, finding overlaps above 99%
The ion-cavity quantum interface is an important building block for tomorrow's quantum networks, but miniaturizing such devices remains an outstanding challenge. This study introduces and characterizes an on-chip design that uses microelectromechanical-systems (MEMS) technology to integrate a fiber-based optical resonator with an ion trap. Simulations show that the device's performance is expected to be similar to that of much larger existing systems, and that it is compatible with strong ion-ca
We herein report a simultaneous frequency stabilization of two 780-nm external cavity diode lasers using a precision wavelength meter (WLM). The laser lock performance is characterized by the Allan deviation measurement in which we find σy=10-12 at an averaging time of 1000 s. We also obtain spectral profiles through a heterodyne spectroscopy, identifying the contribution of white and flicker noises to the laser linewidth. The frequency drift of the WLM is measured to be about 2.0(4) MHz over 36
We investigate a scheme for observing the third-order exceptional point (EP3) in an ion–cavity setting. In the lambda-type level configuration, the ion is driven by a pump field, and the resonator is probed with another weak laser field. We exploit the highly asymmetric branching ratio of an ion's excited state to satisfy the weak-excitation limit, which allows us to construct the non-Hermitian Hamiltonian (HnH). Via fitting the cavity-transmission spectrum, the eigenvalues of HnH are obtained.
Abstract We report the development of an ultrahigh- Q aluminum superconducting microwave resonator on diamond. Our lumped-element LC resonator consists of a central inductive wire, interdigitated comb fingers and signal coupling pads. The resonance frequency of the ground-state mode is measured to be 2.80 GHz with a maximum internal quality factor of 1.0 × 10 6 at 20 mK. Replacing the micron-scale inductive wire with a nanometric one, our resonator will make it possible to detect and manipulate
This study demonstrates the appearance of super intense and wide Mie bandgaps in metamaterials composed of tellurium, germanium, and silicon rods in air that tolerate some disordering of rod position and rod radius under transverse magnetic (TM) polarized light waves. Tellurium metamaterials reveal [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] Mie bandgap modes in which [Formula: see text], [Formula: see text], and [Formula: see text] tol
In this study, we design ultra-broadband optical absorbers, ultra-narrow optical waveguides, and ultra-small optical cavities comprising two-dimensional metallic photonic crystals that tolerate fabrication imperfections such as position and radius disorderings. The absorbers containing gold rods show an absorption amplitude of more than 90% under 54% position disordering at 200<λ<530 nm. The absorbers containing silver rods show an absorptance of more than 90% under 54% position disordering at 2
Cavity-based quantum node is a competitive platform for distributed quantum networks. Here, we characterize a high-finesse Fabry-Pérot optical resonator for coupling single or few atomic quantum registers. Our cavity consists of two mirrors with different reflectivities: One has minimal optical loss, and the other high transmission loss where more than 90% of the intracavity photons would be emitted. Cavity finesse, birefringent effects, and mechanical resonances are measured using the lasers at
We characterize a high-finesse Fabry-Perot resonator for coupling with single neutral atoms. Our cavity consists of two mirrors with different reflectivities: One has minimal optical loss, and the other high transmission loss where more than 90% of the intracavity photons would be emitted. Cavity finesse, birefringent effects, and mechanical resonances are measured using the lasers at 780, 782, and 795 nm. In order to obtain cavity geometric parameters, we drive the adjacent longitudinal or tran