arXiv subjects

Sid C. Wright

Publications and source records attributed to Sid C. Wright.

4 recordsLinked to original sources

arXiv2026

Magnetic atoms with a large electric dipole moment

We experimentally show that an electric dipole moment of more than 1 Debye can be induced in the dysprosium (Dy) atom, in a long-lived state that is about 17513 cm$^{-1}$ above the ground state. This metastable state is part of a strongly coupled opposite-parity doublet. Using optically detected microwave spectroscopy in an atomic beam, we determine the approximately 1.12 cm$^{-1}$ doublet spacing for the five stable bosonic isotopes of Dy with kHz-level accuracy. From the shift of the microwave transition frequency in low electric fields (below 150 V/cm) and from optical spectra in high electric fields (up to 150 kV/cm), a reduced transition dipole moment of 7.65 $\pm$ 0.05 Debye between the doublet states is extracted. In high electric fields the doublet interacts with a third state at 17727 cm$^{-1}$, that connects to the ground state via an electric-dipole transition. The three-state Stark interaction enables preparation of Dy atoms in the metastable state via single-photon excitation from the ground state.

physics.atom-ph↗

arXiv2023

Hyperfine structure and isotope shifts of the $^1P_1 \leftarrow{} ^{1}S_0$ transition in atomic zinc

We report absolute frequency, isotope shift, radiative lifetime and hyperfine structure measurements of the $^1P_1 \leftarrow{} ^{1}S_0$ (213.8 nm) transition in Zn I using a cryogenic buffer gas beam. Laser-induced fluorescence is collected with two orthogonally oriented detectors to take advantage of differences in the emission pattern of the isotopes. This enables clear distinction between isotopes whose resonances are otherwise unresolved, and a measurement of the fermion hyperfine structure parameters, $A(^{67}$Zn)$=20(2)$ MHz and $B(^{67}$Zn)$=10(5)$ MHz. We reference our frequency measurements to an ultralow expansion cavity and achieve an uncertainty at the level of 1 MHz, about 1 percent of the natural linewidth of the transition.

physics.atom-ph↗

arXiv2023

Observation of quantum interference of optical transition pathways in Doppler-free two-photon spectroscopy and implications for precision measurements

Doppler-free two-photon spectroscopy is a standard technique for precision measurement of transition frequencies of dipole-forbidden transitions. The accuracy of such measurements depends critically on fitting of the spectrum to an appropriate line shape model, often a Voigt profile which neglects the effect of quantum interference of optical transitions. Here, we report the observation of quantum interference of optical transition pathways in Doppler-free two-photon spectroscopy of the cesium 6S-7D transitions. The quantum interference manifests itself as asymmetric line shapes of the hyperfine lines of the 7D states, observed through spontaneous emission following excitation by a narrow-linewidth cw laser. The interference persists despite the lines being spectrally well-resolved. Ignoring the effect of quantum interference causes large systematic shifts in the determination of the line-centers, while accounting for it resolves the apparent line shift and enables the precise determination of hyperfine splitting in the 7D states. We calculate the spectral line shape including the effect of quantum interference and show that it agrees with the experimental observations. Our results have implications for precision measurements of hyperfine splittings, isotope shifts and transition frequencies, including those of the hydrogen S-S and S-D transitions.

physics.atom-ph↗

arXiv2022

High-resolution isotope-shift spectroscopy of Cd I

We present absolute frequency measurements of the ${}^{1}\text{P}_1 \leftarrow {}^{1}\text{S}_0$ ($229$nm) and ${}^{3}\text{P}_1 \leftarrow {}^{1}\text{S}_0$ ($326$nm) transitions for all naturally occurring isotopes of cadmium. The isotope shifts and hyperfine intervals of the fermionic isotopes are determined with an accuracy of 3.3MHz. We find that quantum interference in the laser-induced fluorescence spectra of the ${}^{1}\text{P}_1 \leftarrow {}^{1}\text{S}_0$ transition causes an error of up to 29(5)MHz in determining the hyperfine splitting, when not accounted for with an appropriate model. Using a King-plot analysis, we extract the field- and mass-shift parameters and determine nuclear charge radius differences for the fermions. The lifetime of the $^1\text{P}_1$ state is determined to be 1.60(5)ns by measuring the natural linewidth of the ${}^{1}\text{P}_1 \leftarrow {}^{1}\text{S}_0$ transition. These results resolve significant discrepancies among previous measurements.

physics.atom-ph↗