# Direct loading of nanoparticles under high vacuum into a Paul trap for levitodynamical experiments

## TL;DR

This paper presents a novel technique for loading nanoparticles into a Paul trap at ultrahigh vacuum pressures using laser-induced acoustic desorption, enabling high-efficiency trapping suitable for levitodynamical experiments.

## Contribution

The authors introduce a new method combining laser-induced acoustic desorption and trap potential control for efficient nanoparticle loading at ultra-low pressures.

## Key findings

- Achieved particle loading at pressures as low as 4x10^-7 mbar.
- More than 50% success rate in trapping attempts.
- Method is fast, high throughput, and pressure-independent.

## Abstract

Mechanical oscillators based on levitated particles are promising candidates for sensitive detectors and platforms for testing fundamental physics. The targeted quality factors for such oscillators correspond to extremely low damping rates of the center-of-mass motion, which can only be obtained if the particles are trapped in ultrahigh vacuum (UHV). In order to reach such low pressures, a noncontaminating method of loading particles in a UHV environment is necessary. However, loading particle traps at pressures below the viscous flow regime is challenging due to the conservative nature of trapping forces and reduced gas damping. We demonstrate a technique that allows us to overcome these limitations and load particles into a Paul trap at pressures as low as 4x10^-7 mbar. The method is based on laser-induced acoustic desorption of nanoparticles from a metallic foil and temporal control of the Paul trap potential. We show that the method is highly efficient: More than half of the trapping attempts are successful. Moreover, since trapping attempts can be as short as a few milliseconds, the technique provides high throughput of loaded particles. Finally, the efficiency of the method does not depend on pressure, indicating that the method should be extensible to UHV.