Changes in electric field noise due to thermal transformation of a surface ion trap

• Published in: Physical review. B 2022-07, Vol.106 (3), Article 035409
• Main Authors: Berlin-Udi, Maya, Matthiesen, Clemens, Lloyd, P. N. Thomas, Alonso, Alberto M., Noel, Crystal, Saarel, Benjamin, Orme, Christine A., Kim, Chang-Eun, Nelson, Art J., Ray, Keith G., Lordi, Vincenzo, Häffner, Hartmut
• Format: Article
• Language: English
• Subjects: atom and ion trapping and guiding; coherent control; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; cooling and trapping; interface and surface thermodynamics; ion impact and scattering; MATERIALS SCIENCE; metals; quantum information processing; quantum optics; surface and interfacial phenomena; surface instabilities; surface reconstruction; thin films; trapped ions
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.106.035409

Here, we aim to illuminate how the microscopic properties of a metal surface map to its electric field noise characteristics. In our system, prolonged heat treatments of a metal film can induce a rise in the magnitude of the electric field noise generated by the surface of that film. We refer to this heat-induced rise in noise magnitude as a thermal transformation. The underlying physics of this thermal transformation process is explored through a series of heating, milling, and electron treatments performed on a single surface ion trap. Between these treatments, 40Ca+ ions trapped 70 μm above the surface of the metal are used as detectors to monitor the electric field noise at frequencies close to 1 MHz. An Auger spectrometer is used to track changes in the composition of the contaminated metal surface. With these tools we investigate contaminant deposition, chemical reactions, and atomic restructuring as possible drivers of thermal transformations.