Quantum sensing of matter waves using BEC oscillations

Abstract

Detecting matter waves in modern atom circuits is one of the most important operations for feasible applications. Here, we propose a sensor to monitor matter waves in atom circuits. The operation of this sensor is based on the interaction between two different Bose–Einstein condensate (BEC) species in which one of the species is non-self-interacting and is restricted to perform coherent oscillations between the non-central wells of a triple-well potential (TWP). The detection, in the atom circuit to be monitored, occurs when the central well of the TWP is coupled to the circuit. Here, to simulate the regular operation of an atom circuit, we consider BEC matter waves propagating along a ring-shaped optical lattice (OL). We demonstrate numerically and analytically that this coupling leads to a variation of the BEC-oscillation period due to matter waves transiting the sensor. In particular, we show that small fluctuations of the matter waves can be detected by the variations of the BEC-oscillation period. As an example, by using a time–frequency wavelet analysis of the evolution of the population imbalance between the non-central wells of the sensor, we show the feasibility of coherent BEC oscillations to detect and accurately scan bright solitons moving in the ring-shaped OL.