Excited-Band Bloch Oscillations for Precision Atom Interferometry

TL;DR

This paper introduces a novel method using excited-band Bloch oscillations to enhance atom interferometry precision by achieving larger momentum separation with high efficiency and minimal phase noise.

Contribution

The authors demonstrate a new approach employing excited-band Bloch oscillations for high-efficiency, low-noise momentum transfer in atom interferometers, enabling larger separations and improved measurement precision.

Findings

Achieved up to 40ħk momentum transfer using excited-band Bloch oscillations.

Maintained high transfer efficiency (>99.4%) per photon recoil.

Minimized lattice-induced phase fluctuations to less than 1 milliradian per recoil.

Abstract

We propose and demonstrate a method to increase the momentum separation between the arms of an atom interferometer and thus its area and measurement precision, by using Bloch oscillations (BOs) in an excited band of a pulsed optical standing wave lattice. Using excited bands allows us to operate at particular "magic" depths, where high momentum transfer efficiency ($>99.4\%$ per $\hbar k$, where $\hbar k$ is the photon momentum) is maintained while minimizing the lattice-induced phase fluctuations ($<1\,$milliradian per $\hbar k$) that are unavoidable in ground-band BOs. We apply this method to demonstrate interferometry with up to 40$\hbar k$ momenta supplied by BOs. We discuss extensions of this technique to larger momentum transfer and adaptations towards metrological applications of atom interferometry such as a measurement of the fine-structure constant.