Measurement of the secular motion frequency and the space charge density in the linear ion trap

This paper reports that a cloud of laser-cooled ⁴⁰Ca⁺ is successfully trapped and manipulated in the home-built linear ion trap constructed for quantum information processing (QIP). The frequency of the secular motion and the space charge density of the ion cloud are measured, which help knowing the characteristic of the trapping potential and are the prerequisite of QIP with the trapped ions.