Sympathetic cooling of charged particles in Penning traps using electron cyclotron radiation

TL;DR

This paper introduces a novel sympathetic cooling method for charged particles in Penning traps using electron cyclotron radiation, enabling ultra-cold motional states for advanced physics experiments.

Contribution

It proposes a new technique utilizing self-cooled electrons in separate traps for sympathetic cooling, with a quantum-mechanical description and initial experimental implementation.

Findings

Electrons decay to their motional ground state via cyclotron radiation.

The technique achieves extremely low temperatures in motional degrees of freedom.

First experimental results are presented from the ELCOTRAP setup.

Abstract

We present a new technique for cooling arbitrary charged particles in a Penning trap by utilizing self-cooled electrons stored in a separate, macroscopically distant Penning trap as the cooling medium. The electrons decay predominantly to their motional ground state by emission of cyclotron radiation, which results in extremely low temperatures in the realm of single-digit quantum numbers in the motional degrees of freedom of the sympathetically cooled particle species. This opens up an exciting new frontier of tests of fundamental physics in Penning traps. This article provides a conceptual overview as well as a quantum-mechanical description of the involved cooling dynamics. The first implementation of this technique is currently being realized at the dedicated ELCOTRAP experiment at the Max Planck Institute for Nuclear Physics, which introduces special features for a quick iterative technical development cycle. Its current status, first results from commissioning, and future prospects will be presented.