Sympathetic cooling and detection of molecular ions in a Penning trap

Abstract

We have trapped and sympathetically cooled the molecular ions [Formula Presented] and [Formula Presented] in a Penning trap. Through their Coulomb interaction with laser-cooled [Formula Presented] ions the molecules were sympathetically cooled to cryogenic temperatures. We identify the molecules through a measurement of their characteristic mass-dependent breathing mode frequencies. From a measurement of the temperature of the [Formula Presented] ions we estimate that the final temperature of the sympathetically cooled molecules is 4 K. © 1999 The American Physical Society.