A Magic Lattice-Trapped Atom Interferometer using Yb BECs*

Trapped atom interferometry is a promising platform for precision measurement and quantum sensing [1,2]. Compared to their free-falling counterparts, where the interferometer times are limited to typically less than a second, trapped atom interferometers have demonstrated more than a minute of coherence [3]. However, the confining potential used for trapping introduces decoherence channels that limit both the spatial separation and the total interferometer time. In a vertically-oriented optical lattice, Bloch oscillations (BOs) due to the gravitational force on the atoms from the Earth are present. Using BECs of 174Yb in a Multi-path Stuckelberg interferometer, we have recently investigated the phases associated with BOs of relevance for high-accuracy interferometric sensing [4]. In earlier work, we also demonstrated phase-stability in a BO-enhanced Mach-Zehnder atom interferometer operated at the “magic depth” in an excited band of the lattice [5]. At this special depth, BO-phases become first-order insensitive to lattice intensity fluctuations.

Building on our ability to coherently control the wavefunction of atoms in an optical lattice and the magic condition of BOs in an excited band, we demonstrate lattice-trapped atom interferometers using a BEC atom source in both the ground band and first excited band. We will report on work towards comparing interferometer performance in the ground band and magic-depth excited band for different interferometer arm separations and lattice hold times.

[1] Panda et al., 2024. Nature 631, 515-520.

[2] Zhang et al., 2016. PRA 94, 043608.

[3] Panda et al., 2024. Nature Physics 20, 1234-1239.

[4] Rahman et al., 2024. PRR 6, L022012.

[5] McAlpine et al., 2020. PRA 101, 023614.