Improved delta-kick cooling with multiple non-ideal kicks

TL;DR

This paper introduces a novel multi-pulse delta-kick cooling method using compound matter-wave lens systems with Gaussian potentials, significantly improving cooling performance by mimicking harmonic potentials.

Contribution

It proposes a new approach employing multiple non-ideal kicks to enhance delta-kick cooling, inspired by aberration cancellation techniques in optics.

Findings

Achieves a 2.5-fold reduction in kinetic temperature with two pulses.

Achieves a 3.2-fold reduction with three pulses.

Demonstrates potential for improved cooling in realistic experimental setups.

Abstract

Delta-kick cooling is a technique employed to achieve low kinetic temperatures by decreasing momentum width at the cost of increased position width. In an ideal implementation, this method uses a harmonic potential to deliver a single near-instantaneous momentum kick. In practice, potentials that are approximately harmonic near their center are commonly used. As a result, the breakdown of the harmonic approximation far from the center limits the cooling performance. Inspired by aberration cancellation in optics, we propose to use compound matter-wave lens systems for $\delta-$kick cooling with Gaussian potentials. By strategically combining attractive and repulsive kicks, we show that it is possible to mimic the effect of a harmonic potential. For a test case with reasonable experimental parameters, our method suggests a reduction in kinetic temperature by a factor of $2.5$ using a 2-pulse sequence and by a factor of $3.2$ using a 3-pulse sequence.