Abstract

We report our progress in developing a low-power, high-stability miniature atomic frequency standard based on trapped 171Yb+ ions. In our scheme, the ions are buffer-gas cooled and held in a linear quadrupole trap that is integrated into a sealed, getter-pumped vacuum package, and interrogated on the 12.6 GHz hyperfine transition. We hope to achieve a long-term fractional frequency stability of 10-14 with a complete miniature clock. In the first phase of the project we successfully demonstrated a clock system based in a 10 cm3 ion trap metal vacuum package with no active pumping and all components, excluding the probe laser, contained in a portable box. In the current phase we are exploring new techniques to further reduce the size of the vacuum package and other components as well as the integration of the ion trap package with other key elements of the frequency standard, which include miniaturized light sources at 369 and 935 nm and a microfabricated source of Yb for loading the trap. We have also performed a study of how ion motion in the trap in the presence of field gradients can affect the clock resonance linewidth and the required bias field. We have simulated the ion motion to study this effect and observed it in several traps. We will discuss this study in addition to the clock performance.