# Engineering momentum profiles of cold-atom beams

## TL;DR

This paper presents a method to engineer cold-atom beams with specific momentum profiles by using a filter potential, enabling precise control over atomic beam properties for quantum probing applications.

## Contribution

It introduces an algorithm to design filter potentials for tailored momentum profiles in cold-atom beams, including a narrow band-pass filter example.

## Key findings

- Successfully designed a narrow band-pass quantum filter
- Demonstrated potential for probing Bose polarons' properties
- Provided a framework for custom momentum profile engineering

## Abstract

We describe a procedure for engineering beams of cold atoms by selectively draining particles from a trapped gas based on momenta. Atoms escape through a filter potential that only transmits atoms with the desired momenta. We outline an algorithm that outputs a filter potential that produces a pre-specified beam momentum profile. We illustrate this procedure for the case of a narrow band-pass (NBP) quantum filter. Lastly, we discuss the application of the NBP filter for probing the self-energy and effective mass of Bose polarons, as well as the corresponding Landau criterion.