Southwest Quantum Information and Technology

Controlled Carbon Contamination of a Surface Ion Trap

Presenting Author: Benjamin Saarel, University of California Berkeley

Electric field noise is an important error source for high-fidelity operation of ion trap quantum processors. This noise is orders of magnitude larger than expected from known noise sources. Cleaning the trap surface reduces the measured surface contamination and reduces the measured noise, suggesting contamination is responsible for a significant portion of the noise. One of main surface contaminants observed on nearly all trap surfaces is carbon and at least two studies have correlated the amount of surface carbon contamination with the amount of measured noise during a cycle of cleaning. However, different cleaning methods that all successfully remove contamination lead to very different reductions in noise, suggesting the cleaning methods modify the surface in ways besides removing material. In order to study the effect carbon contamination has on surface noise while avoiding additional effects cleaning may have on the surface, our current experiment uses electron-beam-induced deposition using an ethylene precursor gas to deposit several monolayers of carbon onto the surface of an ion trap. Initial measurements of the noise before and after deposition suggests an order-of-magnitude increase in noise due to the carbon contamination. A second deposition experiment with a new trap is underway to confirm these results.

(Session 5 : Thursday from 5:00 pm - 7:00 pm)