Measuring and understanding electric field noise from bulk material and surfaces is important for many areas of physics. In this work, we introduce a method to detect in situ different sources of electric field noise using a single trapped ion as a sensor. We demonstrate the probing of electric field noise as small as SE=5.2(11)×10−16V2m−2Hz−1, the lowest noise level observed with a trapped ion to our knowledge. Our setup incorporates a controllable noise source utilizing a high-temperature superconductor. This element allows us, first, to benchmark and validate the sensitivity of our probe. Second, to probe non-invasively bulk properties of the superconductor, observing for the first time a superconducting transition with an ion. For temperatures below the transition, we use our setup to assess different surface noise processes. The measured noise shows a crossover regime in the frequency domain, which cannot be explained by existing surface noise models. Our results open perspectives for new models in surface science and pave the way to test them experimentally.
@article{arxiv.1805.00793,
title = {Observation of superconductivity and surface noise using a single trapped ion as a field probe},
author = {K. Lakhmanskiy and P. C. Holz and D. Schärtl and B. Ames and R. Assouly and T. Monz and Y. Colombe and R. Blatt},
journal= {arXiv preprint arXiv:1805.00793},
year = {2019}
}