Polarization of electric field noise near metallic surfaces

TL;DR

This paper investigates the polarization characteristics of electric field noise near metallic surfaces, particularly in ion traps, to distinguish between surface-induced and technical noise sources, aiding in understanding and mitigating decoherence in quantum systems.

Contribution

It introduces a method to analyze and measure noise polarization in ion traps, enabling differentiation between surface and technical noise sources.

Findings

Surface noise and technical noise have distinct polarization signatures.

The method can infer surface noise magnitude despite technical noise presence.

Polarization analysis helps improve quantum operation fidelity.

Abstract

Electric field noise in proximity to metallic surfaces is a poorly understood phenomenon that appears in different areas of physics. Trapped ion quantum information processors are particular susceptible to this noise, leading to motional decoherence which ultimately limits the fidelity of quantum operations. On the other hand they present an ideal tool to study this effect, opening new possibilities in surface science. In this work we analyze and measure the polarization of the noise field in a micro-fabricated ion trap for various noise sources. We find that technical noise sources and noise emanating directly from the surface give rise to different degrees of polarization which allows us to differentiate between the two noise sources. Based on this, we demonstrate a method to infer the magnitude of surface noise in the presence of technical noise.