Non-destructive cavity QED probe of Bloch oscillations in a gas of ultracold atoms

TL;DR

This paper proposes a non-destructive cavity QED method to measure Bloch oscillations in ultracold atoms within an optical lattice, enabling high-precision, real-time atomic dynamics monitoring.

Contribution

It introduces a novel cavity-based probing scheme that uses existing lattice fields for non-invasive measurement of atomic motion in optical lattices.

Findings

Achieves high signal-to-noise ratio up to 10^4.

Allows single-run measurement of atomic dynamics.

Demonstrates application to gravitationally induced Bloch oscillations.

Abstract

We describe a scheme for probing a gas of ultracold atoms trapped in an optical lattice and moving in the presence of an external potential. The probe is non-destructive and uses the existing lattice fields as the measurement device. Two counter-propagating cavity fields simultaneously set up a conservative lattice potential and a weak quantum probe of the atomic motion. Balanced heterodyne detection of the probe field at the cavity output along with integration in time and across the atomic cloud yield information about the atomic dynamics in a single run. The scheme is applied to a measurement of the Bloch oscillation frequency for atoms moving in the presence of the local gravitational potential. Signal-to-noise ratios are estimated to be as high as $10^4$.