Applied Physics Express

Magnetic shield integration for a chip-scale atomic clock

Hyun-Gue Hong, Jongcheol Park, Tae Hyun Kim, Hee Yeoun Kim, Sang Eon Park, Sang-Bum Lee, Myoung-Sun Heo, Taeg Yong Kwon

Published Sep 8, 2020• 12 citations

Abstract

We introduce a miniaturized magnetic shield integrated into the physics package of a chip-scale atomic clock. The primary shield, which is formed by a stack of precision-machined high-permeability plates, compactly sits inside the package as it is designed to be the internal supporting frame. Further improved by a Kovar lid, the best frequency sensitivity to a longitudinal external field is 1.1(3) × 10 −11 / μ T, which is consistent with the measured shielding factor, while the transverse sensitivity is well below 10 −12 / μ T. The sealed unit on a chip carrier alone allows stable clock operation with a frequency instability of 4.8(2) × 10 −12 at 1000 s.

DOI: 10.35848/1882-0786/abb642

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