arXiv subjects

Narupon Chattrapiban

Publications and source records attributed to Narupon Chattrapiban.

3 recordsLinked to original sources

arXiv2026

Simple Magneto-Optical and Magnetic Traps for Dysprosium

Dysprosium (Dy) is the most magnetic element on the periodic table, making it excellent for studying dipolar atom-atom interactions. We report on a simple Dy MOT that captures atoms directly from the thermal beam using a single diode-laser system to generate the light. Additionally, the atoms are magnetically confined by the quadrupole magnetic field that also facilitates the MOT. The MOT loading time is $τ_\text{b} = 26~\text{ms}$. Atoms can decay to a dark state that is magnetically trapped. The time constant for loading into this magnetic trap is $τ_\text{d} = 410~\text{ms}$. The total magnetically trapped population is $1.14\times10^{5}$ atoms, with $85\%$ residing in the dark states. The magnetically trapped atoms have a temperature of $28~μ\text{K}$, significantly below the Doppler limit. This population fulfills the requirements for a range of future experiments.

physics.atom-ph↗

arXiv2025

Gravitational Wave Effects on Radio Spectral Lines of Atomic Hydrogen: Hyperfine Splitting and Broadening Mechanisms

We explore the effects of gravitational waves (GWs) on hydrogen's radio spectral lines, focusing on the ground-state hyperfine transition and radiative transitions in highly excited Rydberg states. To analyze GW impacts on hyperfine structure, we derive Maxwell's equations in a gravitational-wave background using linearized gravity and the $3+1$ formalism. Our findings reveal that GWs induce energy shifts in hyperfine magnetic substates, modifying the 21 cm line. However, these energy shifts fall well below the detection limits of current radio astronomical instruments. For transitions in highly excited states, which produce radio recombination lines (RRL), the influence of GW manifests itself as spectral broadening, with the fractional linewidth for $\mathrm{H}n\alpha$ scaling as $\Delta\nu/\nu_0 \sim n^7\omega^2_{\mathrm{gw}}h(t)$. This suggests that RRLs could serve as probes for ultra-high-frequency GWs, particularly given that Rydberg atoms in the interstellar medium can reach quantum numbers above $n=100$. As an example of possibly detectable high frequency GW source, We investigate GWs emitted during the inspiral of planetary-mass primordial black hole binaries, where GW-induced broadening in RRLs could exceed natural broadening effects. Additionally, we examine the influence of the recently detected stochastic gravitational-wave background on hydrogen spectral lines.

gr-qc↗

arXiv2023

The effects of gravitational waves on a hydrogen atom

We investigate the influence of gravitational waves on a freely falling hydrogen atom by analyzing the dynamics of the bound electron described by the Dirac equation in the curved spacetime of a gravitational wave. From this, we derive the corresponding Dirac Hamiltonian in the Local Inertial Frame of the atom, assuming gravitational waves are described by the linearized theory of General Relativity. To maintain meaningful physical interpretations while obtaining a non-relativistic description, we employ the Foldy-Wouthuysen transformation. Through the analysis of resulting interaction terms and comparison with flat spacetime counterparts, valuable insights into the effects of gravitational waves on the hydrogen atom are gained. Additionally, we explore selection rules governing the coupling between gravitational waves and the atom and utilize first-order perturbation theory to quantify the induced energy shifts and spectral line splitting. This investigation contributes to our understanding of the interplay between quantum systems and gravitational waves, which could lead to alternative method of gravitational waves indirect detection. However, measuring such tiny energy shifts would require a telescope with very high spectral resolution.

gr-qc↗