Fabrication and heating rate study of microscopic surface electrode ion traps

TL;DR

This study measures and analyzes the heating rates of a microfabricated surface electrode ion trap, revealing surface contamination as a key factor influencing increased heating over time.

Contribution

It provides detailed heating rate measurements of a gold-on-sapphire ion trap and links surface contamination to increased heating, offering insights into noise sources.

Findings

Heating rates increase by about tenfold over months

Surface contamination significantly impacts trap heating

Noise spectral density aligns with room temperature ion traps

Abstract

We report heating rate measurements in a microfabricated gold-on-sapphire surface electrode ion trap with trapping height of approximately 240 micron. Using the Doppler recooling method, we characterize the trap heating rates over an extended region of the trap. The noise spectral density of the trap falls in the range of noise spectra reported in ion traps at room temperature. We find that during the first months of operation the heating rates increase by approximately one order of magnitude. The increase in heating rates is largest in the ion loading region of the trap, providing a strong hint that surface contamination plays a major role for excessive heating rates. We discuss data found in the literature and possible relation of anomalous heating to sources of noise and dissipation in other systems, namely impurity atoms adsorbed on metal surfaces and amorphous dielectrics.