Abstract

The motion of trapped ions can be observed as sidebands on an optical [1] or microwave transition [2]. We will demonstrate the potential of measuring the ion motion in a Paul trap by means of self-induced Zeeman coherences [3]. Ions in a rf-trap which are oscillating in a magnetic field with small field gradient, undergo a sublevel transition between adjacent Zeeman levels, when the level splitting and by this the Larmor frequency ω_L= (µ_B/ħ)gJ B2 in the field is equal to the vibration frequency of the ions in the trap. This phenomenon in combination with the method of optical pumping is used to measure the whole motional spectrum of the ions with high resolution (Δν ≃ 500 Hz).

© 1996 IEEE