Heating of trapped ions from the quantum ground state - art. no. 063418

We have investigated motional heating of laser-cooled Be-9(+) ions held in radio-frequency (Paul) traps. We have measured heating rates in a variety o f traps with different geometries, electrode materials, and characteristic sizes. The results show that heating is due to electric-field noise from th e trap electrodes that exerts a stochastic fluctuating force on the ion. Th e scaling of the heating rate with trap size is much stronger than that exp ected from a spatially uniform noise source on the electrodes (such as John son noise from external circuits), indicating that a microscopic uncorrelat ed noise source on the electrodes (such as fluctuating patch-potential fiel ds) is a more likely candidate for the source of heating.