Electric-field noise from thermally-activated fluctuators in a surface ion trap
Electric field noise is a major limiting factor in the performance of ion traps and other quantum devices. Despite intensive research over the past decade, the nature and cause of electric field noise near surfaces is not very well understood . We probe electric-field noise near the surface of an ion trap chip in a previously unexplored high-temperature regime. A saturation of the noise amplitude occurs around 500 K, which, together with a small change in the frequency scaling, points to thermally activated fluctuators as the origin of the noise. The data can be explained by a broad distribution of activation energies around 0.5 eV. These energies suggest atomic displacements as a relevant microscopic mechanism, likely taking place at the metal surface.
 M. Brownnutt, M. Kumph, P. Rabl, and R. Blatt, Reviews of Modern Physics 87, 1419 (2015)