# Trapped-ion probing of light-induced charging effects on dielectrics - Quantum Physics

Abstract: We use a string of confined $^{40}$Ca$^+$ ions to measure perturbations to atrapping potential which are caused by light-induced charging of ananti-reflection coated window and of insulating patches on the ion-trapelectrodes. The electric fields induced at the ions- position are characterisedas a function of distance to the dielectric, and as a function of the incidentoptical power and wavelength. The measurement of the ion-string position issensitive to as few as $40$ elementary charges per $\sqrt{\mathrm{Hz}}$ on thedielectric at distances of order millimetres, and perturbations are observedfor illumination with light of wavelengths as long as 729\,nm. This hasimportant implications for the future of miniaturised ion-trap experiments,notably with regards to the choice of electrode material, and the optics thatmust be integrated in the vicinity of the ion. The method presented can bereadily applied to the investigation of charging effects beyond the context ofion trap experiments.

Author: Maximilian Harlander, Michael Brownnutt, Wolfgang Hänsel, Rainer Blatt

Source: https://arxiv.org/