In situ detection of RF breakdown on microfabricated surface ion traps

TL;DR

This paper presents two new in situ methods for detecting RF breakdown in microfabricated surface ion traps, revealing that breakdown can occur after delays and suggesting voltage ramping to prevent damage.

Contribution

Introduction of two novel in situ detection techniques for RF breakdown in surface ion traps and insights into breakdown timing and damage mechanisms.

Findings

Breakdown can occur minutes or hours after increasing RF voltage.

Visible damage increases with applied RF voltage.

Gradual voltage ramping can reduce damage risk.

Abstract

Microfabricated surface ion traps are a principle component of many ion-based quantum information science platforms. The operational parameters of these devices are pushed to the edge of their physical capabilities as the experiments strive for increasing performance. When the applied radio-frequency (RF) voltage is increased too much, the devices can experience damaging electric discharge events known as RF breakdown. We introduce two novel techniques for in situ detection of RF breakdown, which we implemented while characterizing the breakdown threshold of surface ion traps produced at Sandia National Laboratories. In these traps, breakdown did not always occur immediately after increasing the RF voltage, but often minutes or even hours later. This result is surprising in the context of the suggested mechanisms for RF breakdown in vacuum. Additionally, the extent of visible damage caused by breakdown events increased with applied voltage. To minimize the probability for damage when RF power is first applied to a device, our results strongly suggest that the voltage should be ramped up over the course of several hours and monitored forbreakdown.