arXiv subjects

Yongwoong Lee

Publications and source records attributed to Yongwoong Lee.

3 recordsLinked to original sources

arXiv2026

Spectroscopy of the $\mathbf{X^2Σ^+(v=2) \rightarrow A^2Π_{1/2}(v=1)}$ Transition in MgF: Hyperfine Structures and Spectroscopic Constants

We report spectroscopic results of the $X^2Σ^+(v=2) \rightarrow A^2Π_{1/2}(v=1)$ transition in magnesium monofluoride (MgF). Using Doppler-free Laser-Induced Fluorescence (LIF) spectroscopy on the $X^2Σ^+(v=2) \rightarrow A^2Π_{1/2}(v=1)$ transition, we resolved 47 hyperfine components distributed over 11 transition lines in X and A states. An effective Hamiltonian -- comprising contributions from vibrational, rotational, $Λ$-doubling, and hyperfine interactions -- was presented to model the energy structure of the $A^2Π_{1/2}(v=1)$ state. The spectroscopic parameters, including the rotational constant, the $Λ$-doubling parameter, and the hyperfine interaction constants, were extracted using a least-square fitting and Markov Chain Monte Carlo (MCMC) procedure. Our study reveals that the spectroscopic constants show subtle changes compared to the $A^2Π_{1/2}(v=0)$ state. These results provide critical spectroscopic benchmarks for optimizing optical cycling schemes in MgF, thereby advancing optical cycling efficiency in the magneto-optical trapping of MgF.

physics.atom-ph↗

arXiv2025

Optical cycling of MgF molecules within the hyperfine states in X(N=1) state

We investigated the optical cycling effect of the $\mathrm{X}^2Σ(v=0,\ N=1^-) - \mathrm{A}^2Π_{1/2}(v'=0,\ J'=1/2^+)$ band of MgF molecules, specifically the $\mathrm{P_1/Q_{12}(1)}$ transition, which serves as the main transition in the quasi-closed cycling scheme for the laser cooling. A higher number of scattered photons was observed when all three frequency components of the $\mathrm{P_1/Q_{12}(1)}$ transition were simultaneously applied using acousto-optic modulators (AOMs). Optimal conditions were identified by scanning the detuning of frequency components, the laser beam power ratio, and the total laser beam power, and the results were confirmed through rate equation simulations. Under these optimized conditions, and with an applied magnetic field, the scattering rate was enhanced by approximately a factor of six. These results refine the implementation of optical cycling in MgF and lay the groundwork for laser slowing and magneto-optical trapping (MOT) experiments.

physics.atm-clus↗

arXiv2024

Machine learning-enhanced optical tweezers for defect-free rearrangement

Optical tweezers constitute pivotal tools in Atomic, Molecular, and Optical(AMO) physics, facilitating precise trapping and manipulation of individual atoms and molecules. This process affords the capability to generate desired geometries in both one-dimensional and two-dimensional spaces, while also enabling real-time reconfiguration of atoms. Due to stochastic defects in these tweezers, which cause catastrophic performance degradation especially in quantum computations, it is essential to rearrange the tweezers quickly and accurately. Our study introduces a machine learning approach that uses the Proximal Policy Optimization model to optimize this rearrangement process. This method focuses on efficiently solving the shortest path problem, ensuring the formation of defect-free tweezer arrays. By implementing machine learning, we can calculate optimal motion paths under various conditions, resulting in promising results in model learning. This advancement presents new opportunities in tweezer array rearrangement, potentially boosting the efficiency and precision of quantum computing research.

physics.atom-ph↗