arXiv subjects

William R. McGehee

Publications and source records attributed to William R. McGehee.

3 recordsLinked to original sources

arXiv2026

Wafer-Scale Micro-Knife Sealed Vacuum Cells for Quantum Devices

Advanced integration technologies greatly enhance the prospects and reliability of practical quantum sensors, atomic clocks, and quantum information technologies. The performance and proliferation of these devices at chip-scale is contingent upon developing low leak and low gas permeation vacuum cells using wafer-scale techniques. Here we demonstrate both evacuated atomic beam cells and atomic vapor cells using plastic deformation micro-knife bonding of selectively etched fused silica wafers. The cells are characterized using saturated absorption spectroscopy and fluorescence measurements. Vapor cells are mechanically robust exhibiting sheer-force strength ($\sim 15$MPa), demonstrate long lifetimes ($> 1$ year), low residual gas pressures $ (\ll 10^{-3} \, \text{mbar}) $, and leak rates below fine-leak testing sensitivity ($\ll 2.8 \times 10^{-10} \frac{\text{mBar} \cdot \text{L}}{\text{s}}$). Micro-knife bonding greatly simplifies the fabrication process for complex chip scale atom-beam devices and atomic vapor cells while identifying a path to future chip-scale cold atom devices, improved chip scale atomic clocks, and fieldable dissipation-dilution-limited optomechanics.

physics.atom-ph↗

arXiv2025

A chip-scale atomic beam source for non-classical light

Room temperature thermal atoms have proven to be a powerful resource for magnetometry, electrometry, atom-entanglement generation, and robust atomic clocks. Recent efforts have sought to realize compact and highly manufacturable atomic vapors and atomic beams for chip-scale magnetometry and atomic clocks. Here, we show that a chip-scale rubidium beam source can be integrated with a high finesse cavity-QED system to generate non-classical light. By demonstrating the compatibility of these two technologies, we open a new path for distributed sources of non-classical light and set the stage for using cavity-QED to enhance the performance of chip-scale magnetometers and atomic clocks.

physics.atom-ph↗

arXiv2023

A chip-scale atomic beam clock

Atomic beams are a longstanding technology for atom-based sensors and clocks with widespread use in commercial frequency standards. Here, we report the demonstration a chip-scale microwave atomic beam clock using coherent population trapping (CPT) interrogation in a passively pumped atomic beam device. The beam device consists of a hermetically sealed vacuum cell fabricated from an anodically bonded stack of glass and Si wafers. Atomic beams are created using a lithographically defined microcapillary array connected to a Rb reservoir1 and propagate in a 15 mm long drift cavity. We present a detailed characterization of the atomic beam performance (total Rb flux $\approx 7.7 \times 10^{11} s^{-1}$ at 363 K device temperature) and of the vacuum environment in the device (pressure < 1 Pa), which is sustained using getter materials which pump residual gases and Rb vapor. A chip-scale beam clock is realized using Ramsey CPT spectroscopy of the 87Rb ground state hyperfine transition over a 10 mm Ramsey distance in the atomic beam device. The prototype atomic beam clock demonstrates a fractional frequency stability of $\approx 1.2 \times 10^{-9}/\sqrtτ$ for integration times $τ$ from 1 s to 250 s, limited by detection noise. Optimized atomic beam clocks based on this approach may exceed the long-term stability of existing chip-scale clocks, and leading long-term systematics are predicted to limit the ultimate fractional frequency stability below $10^{-12}$.

physics.atom-ph↗