Electric-field noise in a high-temperature superconducting surface ion trap

Scaling up trapped-ion quantum computers requires new trap materials to be explored. Here we present experiments with a surface ion made from the high-temperature superconductor YBCO, promising material for future designs. We show that voltage noise superconducting electrode leads is negligible within sensitivity ${S}_{V}=9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}\phantom{\rule{0.16em}{0ex}}{\mathrm{V}}^{2}/\mathrm{Hz}$ of our setup, and lead dimensions typical advanced Furthermore, investigate frequency temperature dependence electric-field above YBCO surface. find $1/f$ spectral nontrivial dependence, plateau in stretching over roughly $60\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. The onset coincides transition, indicating connection between dominant material. exclude bulk as origin suggest further decide two remaining options explaining observed dependence: screening phase, or activated by through some unknown mechanism.