arXiv subjects

Jackson Schrott

Publications and source records attributed to Jackson Schrott.

7 recordsLinked to original sources

arXiv2026

Narrow-line magneto-optical trap of titanium atoms

We realize narrow-linewidth magneto-optical traps of $^{46}$Ti, $^{48}$Ti and $^{50}$Ti atoms based on a 1040 nm-wavelength transition, cooling atoms to a minimum temperature in one dimension of $T_z=990(20)$ nK and a three-dimensional temperature of $T_\mathrm{3D}=1.28(7)$ $\mu$K. Atoms are pre-cooled in a broad-line magneto-optical trap and then transferred with about 25% efficiency to the narrow-line trap. We operate the narrow-line trap in two stages over 85 ms. First, a single cooling beam, blue-detuned from the narrow-linewidth atomic resonance, optically pumps and traps the atoms on a two-dimensional surface where the Zeeman shift from the applied spherical quadrupole magnetic field brings the light nearly to resonance. Second, four additional beams, counter-propagating in the transverse directions, cool and compress the atoms in all dimensions. The high magnetic moment of the laser cooling state makes the dynamics of the narrow-line titanium trap similar to those of other magnetic atoms. We measure the lifetime of the excited state of the transition to be $\tau=8.2(9)$ $\mu$s, indicating a transition linewidth of $\gamma/2\pi =20(2)$ kHz, and also measure isotope shifts on the narrow-line transition. We use Stern-Gerlach separation on the ultracold Ti gas to measure the $m_J$-distribution in the narrow-line magneto-optical trap, finding over 98% of the atoms in the stretched spin state.

physics.atom-ph↗

arXiv2026

$\mathrm{^{130}Te_2}$ spectroscopic reference for neutral Ti lines at 391 nm and 498 nm

We report on the use of ditellurium ($\mathrm{^{130}Te_2}$) as a frequency reference for laser locking at 391 nm and 498 nm optical wavelengths, which are of interest in titanium (Ti) laser-cooling experiments. In the ultraviolet region near the optical wavelength of 391 nm, 36 previously unobserved transitions were found using laser absorption spectroscopy in a 256 GHz range. Based on the established molecular structure of $\mathrm{^{130}Te_2}$, we attribute these lines to the $\mathrm{0_u^+\rightarrow 0_g^+}$ subsystem of the $\mathrm{^3\Sigma_u^-\rightarrow\ ^3\Sigma_g^-}$ transition with possible vibrational transitions of $\nu=(28,27,26,25,24)\rightarrow 0$ and $(27,26)\rightarrow 1$. We measure the frequencies of these lines, and also of lines near 498 nm wavelength, and subsequently stabilize lasers at wavelengths of 391 nm (and 498 nm) to $\sim$60 MHz ($\sim$50 MHz) wide resonances in $\mathrm{^{130}Te_2}$, near the optical-pumping (laser-cooling) transitions in $\mathrm{^{48}Ti}$. We observe robust laser frequency locks, with Allan deviations of $4.9\times 10^{-10}$ ($3.6\times 10^{-11}$) at 10 s of averaging time for the 391 nm (498 nm) wavelength lasers.

physics.atom-ph↗

arXiv2026

Hyperfine spectroscopy and laser cooling of the fermionic isotopes $^{47}$Ti and $^{49}$Ti

We report on magneto-optical trapping of the two fermionic isotopes of atomic titanium, $^{47}$Ti and $^{49}$Ti. Unlike the even mass-number isotopes, which were recently laser cooled, $^{47}$Ti and $^{49}$Ti have nonzero nuclear spins and, consequently, their atomic levels are split by hyperfine structure. Combining and comparing theoretical calculations and atomic beam-spectroscopy measurements, we determine the hyperfine structures and isotope shifts of the $\mathrm{3d^24s^2}$ $\mathrm{a^3F_4\rightarrow 3d^2(^3P)4s4p(^3P^o)}$ $\mathrm{y^5D_4^o}$ optical-pumping transition at optical wavelength 391nm and the $\mathrm{3d^3(^4F)4s}$ $\mathrm{a^5F_5\rightarrow 3d^3(^4F)4p}$ $\mathrm{y^5G_6^o}$ laser-cooling transition at wavelength 498nm. With this information, we produce magneto-optical traps of both $^{47}$Ti and $^{49}$Ti by applying two additional tones of light to repump atoms to the maximum-spin states on the laser-cooling transition. Directly loading from the atomic flux of a titanium sublimation pump, we produce $^{47}$Ti and $^{49}$Ti traps with 731(190) and 1142(240) atoms, and with lifetimes of 330(15)ms and 310(8)ms, respectively.

physics.atom-ph↗

arXiv2025

A Magneto-Optical Trap of Titanium Atoms

We realize laser cooling and trapping of titanium (Ti) atoms in a mangeto-optical trap (MOT). While Ti does not possess a transition suitable for laser cooling out of its $\mathrm{3d^24s^2}$ $\mathrm{a^3F}$ ground term, there is such a transition, at an optical wavelength of $\lambda=498\mathrm{nm}$, from the long-lived $\mathrm{3d^3(^4F)4s}$ $\mathrm{a^5F_5}$ metastable state to the $\mathrm{3d^3(^4F)4p}$ $\mathrm{y^5G^o_6}$ excited state. Without the addition of any repumping light, we observe MOTs of metastable $\mathrm{^{46}Ti}$, $\mathrm{^{48}Ti}$, and $\mathrm{^{50}Ti}$, the three stable nuclear-spin-zero bosonic isotopes of Ti. While MOTs can be observed when loaded directly from our Ti sublimation source, optical pumping of ground term atoms to the $\mathrm{a^5F_5}$ state increases the loading rate by a factor of 120, and the steady-state MOT atom number by a factor of 30. At steady state, the MOT of $\mathrm{^{48}Ti}$ holds up to $8.30(26)\times10^5$ atoms at a maximum density of $1.3(4)\times10^{11}\mathrm{cm}^{-3}$ and at a temperature of $90(15)\mathrm{\mu K}$. By measuring the decay of the MOT upon suddenly reducing the loading rate, we place upper bounds on the leakage branching ratio of the cooling transition $(\leq2.5\times 10^{-6})$ and the two-body loss coefficient $(\leq2\times10^{-10}\mathrm{cm}^3\mathrm{s}^{-1})$. Our approach to laser cooling Ti can be applied to other transition metals, enabling a significant expansion of the elements that can be laser cooled.

physics.atom-ph↗

arXiv2024

An Atomic Beam of Titanium for Ultracold Atom Experiments

We generate an atomic beam of titanium (Ti) using a "Ti-ball" Ti-sublimation pump, which is a common getter pump used in ultrahigh vacuum (UHV) systems. We show that the sublimated atomic beam can be optically pumped into the metastable $3d^{3}(^4F){4}s$ $a^5F_5$ state, which is the lower energy level in a nearly cycling optical transition that can be used for laser cooling. We measure the atomic density and transverse and longitudinal velocity distributions of the beam through laser fluorescence spectroscopy. We find a metastable atomic flux density of $4.3(2)\times10^9\,$s$^{-1}$cm$^{-2}$ with mean forward velocity $773(8)\,$m/s at $2.55\,$cm directly downstream of the center of the Ti-ball. Owing to the details of optical pumping, the beam is highly collimated along the transverse axis parallel to the optical pumping beam and the flux density falls off as $1/r$. We discuss how this source can be used to load atoms into a magneto-optical trap.

physics.atom-ph↗

arXiv2023

Optical Telecommunications-Band Clock based on Neutral Titanium Atoms

We propose an optical clock based on narrow, spin-forbidden M1 and E2 transitions in laser-cooled neutral titanium. These transitions exhibit much smaller black body radiation shifts than those in alkaline earth atoms, small quadratic Zeeman shifts, and have wavelengths in the S, C, and L-bands of fiber-optic telecommunication standards, allowing for integration with robust laser technology. We calculate lifetimes; transition matrix elements; dynamic scalar, vector, and tensor polarizabilities; and black body radiation shifts of the clock transitions using a high-precision relativistic hybrid method that combines a configuration interaction and coupled cluster approaches. We also calculate the line strengths and branching ratios of the transitions used for laser cooling. To identify magic trapping wavelengths, we have completed the largest-to-date direct dynamical polarizability calculations. Finally, we identify new challenges that arise in precision measurements due to magnetic dipole-dipole interactions and describe an approach to overcome them. Direct access to a telecommunications-band atomic frequency standard will aid the deployment of optical clock networks and clock comparisons over long distances.

physics.atom-ph↗

arXiv2021

Measurement of the Angular Distribution of Wavelength-Shifted Light Emitted by TPB

We present measurements of the angular distribution of re-emitted light from tetraphenyl butadiene thin films when exposed to \SI{128}{nm} light in vacuum. Films ranging from \SI{250}{nm} to \SI{5.5}{\micron} in thickness are measured. All films were fabricated by evaporation deposition on ultraviolet transmitting (UVT) acrylic substrates. Preliminary comparisons of the angular distribution to that produced by a detailed Monte Carlo model are also presented. The current shortcomings of the model are discussed and future plans briefly outlined.

physics.ins-det↗