Viability of rotation sensing using phonon interferometry in Bose-Einstein condensates

TL;DR

This paper explores using a ring-shaped Bose-Einstein condensate as a rotation sensor by analyzing phonon interference, identifying damping mechanisms, and demonstrating a proof-of-principle rotation measurement with promising sensitivity.

Contribution

The study introduces a phonon-based rotation sensing method in BECs, models phonon decay mechanisms, and demonstrates a significant sensitivity improvement over previous approaches.

Findings

Phonon excitations decay rapidly with quality factors up to 27.

Two Landau scattering processes dominate phonon damping at different conditions.

Experimental rotation sensitivity of 0.3 rad/s, with potential to reach 0.04 rad/s in ideal conditions.

Abstract

We demonstrate the use of a ring-shaped Bose-Einstein condensate as a rotation sensor by measuring the interference between two counter-propagating phonon modes imprinted azimuthally around the ring. We observe rapid decay of the excitations, quantified by quality factors of at most $Q \approx 27$. We numerically model our experiment using the c-field methodology, allowing us to estimate the parameters that maximise the performance of our sensor. We explore the damping mechanisms underlying the observed phonon decay, and identify two distinct Landau scattering processes that each dominate at different driving amplitudes and temperatures. Our simulations reveal that $Q$ is limited by strong damping of phonons even in the zero temperature limit. We perform an experimental proof-of-principle rotation measurement using persistent currents imprinted around the ring. We demonstrate a rotation sensitivity of up to $\Delta \Omega \approx 0.3$ rad/s from a single image, with a theoretically achievable value of $\Delta \Omega \approx 0.04$ rad/s in the atomic shot-noise limit. This is a significant improvement over the shot-noise-limited $\Delta \Omega \approx 1$ rad/s sensitivity obtained by Marti et al. [Phys. Rev. A 91, 013602 (2015)] for a similar setup.