Atomic Physics
We review a few ideas and experiments that our laboratory at Korea University has proposed and carried out to use vector polarizability \beta to manipulate alkali-metal atoms. \beta comes from spin-orbit coupling, and it produces an ac…
The quantum-classical hybrid Variational Quantum Eigensolver (VQE) algorithm is recognized to be the most suitable approach to obtain ground state energies of quantum many-body systems in the noisy intermediate scale quantum era. In this…
The existence of exotic spin-dependent forces may shine light on new physics beyond the Standard Model. We utilize two iron shielded SmCo$_5$ electron-spin sources and two optically pumped magnetometers to search for exotic long-range…
We report precision measurements of the nuclear magnetic moment of \textsuperscript{43}Ca\textsuperscript{+}, made by microwave spectroscopy of the 4s $^2$S$_{1/2}$ $\left|F=4, M=0\right\rangle \rightarrow \left|F=3, M=1\right\rangle$…
We theoretically investigate the trap-assisted formation of complexes in atom-ion collisions and their impact on the stability of the trapped ion. The time-dependent potential of the Paul trap facilitates the formation of temporary…
Current dual-frequency magneto-optical traps for ultracold molecules are plagued by sub-Doppler heating effects, making them vastly inferior to standard atomic MOTs. Here we demonstrate theoretically that the sub-Doppler effects in such a…
The purpose of this paper is to show that, by combining Feshbach resonances with external confining potentials, the energy scale factor of neighboring Efimov states can be tremendously reduced. The Efimov conditions can be reached for…
A full six-dimensional Born-Oppenheimer singlet potential energy surface is constructed for the reaction CaF + CaF $\rightarrow$ CaF$_2$ + Ca using a multireference configuration interaction (MRCI) electronic structure calculation. The {\it…
This tutorial aims to provide details on the underlying principles and methodologies of atom-based terahertz imaging techniques. Terahertz imaging is a growing field of research which can provide complementary information to techniques…
The study of radioisotopes as well as of highly charged ions is a very active and dynamic field. In both cases, the most sensitive probes involve species trapped in Penning or Paul traps after a lengthy series of production and separation…
The Saturated Absorption Spectroscopy (SAS) was performed to measure the hyperfine energy splittings of rubidium 5P$_{1/2}$ excited state using a homemade external-cavity diode laser (ECDL) operating at 795 nm. Any nonlinearities associated…
We formulate a non-relativistic quantum field theory to model interactions between quantized electromagnetic fields and localized charge-current distributions. The electronic degrees of freedom are encoded in microscopic polarization and…
We present results from exploratory studies, supported by the Physics Beyond Colliders (PBC) Study Group, of the suitability of a CERN site and its infrastructure for hosting a vertical atom interferometer (AI) with a baseline of about 100…
The total energy and other bound state properties of the ground (bound) $1^{1}S$-state in the Ps$^{-}$ (or $e^{-}e^{+}e^{-}$) ion are determined to very high accuracy. Our best variational energy for the ground state in this ion equals $E$…
We analyze the phase diffusion, quantum fluctuations and their spectral features of an one-dimensional Bose-Josephson junction (BJJ) coupled to a bosonic heat bath. We show the dependence of the phase diffusion coefficient on the on-site…
Neutral quantum absorbers in optical lattices have emerged as a leading platform for achieving clocks with exquisite spectroscopic resolution. However, the studies of these clocks and their systematic shifts have so far been limited to…
The saturated absorption spectrum of the hyperfine-less S(0) quadrupole line in the (2-0) band of H$_2$ is measured at $\lambda=1189$ nm, using the NICE-OHMS technique under cryogenic conditions (72~K). It is for the first time that a Lamb…
We demonstrate imaging of ions in an atomic gas with ion-Rydberg atom interaction induced absorption. This is made possible by utilizing a multi-photon electromagnetically induced transparency (EIT) scheme and the extremely large electric…
A recently developed version of the configuration interaction (CI) method for open shells with a large number of valence electrons has been used to study two heavy atoms, californium (Cf, Z= 98) and einsteinium (Es, Z= 99). Motivated by…
Attosecond noncollinear four wave mixing spectroscopy with one attosecond extreme ultraviolet (XUV) pulse and two few-cycle near-infrared (NIR) pulses was used to measure the autoionization decay lifetimes of inner valence electronic…