Temperature Dependence of Electric Field Noise Above Gold Surfaces

TL;DR

This study measures how electric field noise above gold surfaces varies with temperature and frequency, revealing a strong temperature dependence that impacts precision experiments like quantum computing.

Contribution

It provides detailed temperature and frequency dependence data of electric field noise above gold surfaces, highlighting a thermal process influencing noise levels.

Findings

Noise amplitude follows a 1/f spectrum around 1 MHz.

Noise grows rapidly with temperature as T^beta, with beta from 2 to 4.

Data aligns with microfabricated cantilever measurements of non-contact friction.

Abstract

Electric field noise from fluctuating patch potentials is a significant problem for a broad range of precision experiments, including trapped ion quantum computation and single spin detection. Recent results demonstrated strong suppression of this noise by cryogenic cooling, suggesting an underlying thermal process. We present measurements characterizing the temperature and frequency dependence of the noise from 7 to 100 K, using a single Sr+ ion trapped 75 um above the surface of a gold plated surface electrode ion trap. The noise amplitude is observed to have an approximate 1/f spectrum around 1 MHz, and grows rapidly with temperature as T^beta for beta from 2 to 4. The data are consistent with microfabricated cantilever measurements of non-contact friction but do not extrapolate to the DC measurements with neutral atoms or contact potential probes.