Angular Bloch Oscillations and their applications

Abstract

Inspired by the fast-developing field of compact and mobile quantum sensors for space- and ground-based applications, we propose a new concept for measuring the angular acceleration of external rotation. For this, we study the dynamics of ultra-cold atoms in a toroidal trap with additional modulation along the angular direction, realized in labs with the superposition of two Laguerre-Gauss (LG) beams with indices l and -l. In the presence of external rotation with small angular acceleration, or by having a well-controllable chirp between the two LG beams, our system is shown to display a new phenomenon we name as the Angular Bloch Oscillations (ABOs). In addition, we show that ABOs can be utilized (i) to precisely transfer certain angular momenta from the field to trapped atoms, by using the slowly varying chirp, and (ii) to determine the angular acceleration of the external rotation, by measuring the Bloch period of ABOs.