Superfluid rotation sensor with helical laser trap

TL;DR

This paper proposes a superfluid rotation sensor utilizing a helical laser trap that encodes rotation into the translational motion of a twisted matter wave, enabling detection of rotation via quantum interference patterns.

Contribution

It introduces a novel superfluid rotation sensor based on a helical laser trap and analyzes the quantum states and dynamics of the atomic ensemble in this configuration.

Findings

Rotation induces translational motion of the matter wave proportional to angular velocity and pattern handedness.

Explicit expressions for linear and angular momentum of the atomic cloud are derived.

The effect can be detected with current laboratory equipment, distinguishing quantum from classical fluids.

Abstract

The macroscopic quantum states of the dilute bosonic ensemble in helical laser trap at the temperatures about $10^{-6}\bf {K}$ are considered in the framework of the Gross-Pitaevskii equation. The helical interference pattern is composed of the two counter propagating Laguerre-Gaussian optical vortices with opposite orbital angular momenta $\ell \hbar$ and this pattern is driven in rotation via angular Doppler effect. Macroscopic observables including linear momentum and angular momentum of the atomic cloud are evaluated explicitly. It is shown that rotation of reference frame is transformed into translational motion of the twisted matter wave. The speed of translation equals the group velocity of twisted wavetrain $V_z= \Omega\ell/ k$ and alternates with a sign of the frame angular velocity $\Omega$ and helical pattern handedness $\ell$. We address detection of this effect using currently accessible laboratory equipment with emphasis on the difference between quantum and classical fluids.