A New Approach to Measurement of Heating Rate of Trapped Ions

D. A. Hite, K. S. McKay, S. Kotler +3 more

You-Yang Xu, Zhou Fei, Yi Xie

We propose a new scheme to estimate the heating rate of trapped ions in thermal states. By applying a controlled-U gate between the internal and the motional states of one of the trapped ions, we could obtain the mean phonon number from the population of the internal state of the ion. The imperfection due to fluctuations of the relevant parameters in real experiments is considered and we analyze the experimental feasibility of our scheme with sophisticated ion trap techniques.

Jiu-Zhou He, L.-L. Yan, Liang Chen +2 more

We report measurement of heating rates of 40 C a + ions confined in our home-made microscopic surface-electrode trap by a Doppler recooling method. The ions are trapped with approximately 800 μ m above the surface, and are subjected to heating due to various noises in the trap. There are 3–5 ions involved to measure the heating rates precisely and efficiently. We show the heating rates in variance with the number and the position of the ions as well as the radio-frequency power, which are helpful for understanding the trap imperfection.

Elisabeth Brama, A. Mortensen, Matthias Keller +1 more

Ivan A. Boldin, Alexander Kraft, Christof Wunderlich

Cold ions trapped in the vicinity of conductive surfaces experience heating of their oscillatory motion. Typically, the rate of this heating is orders of magnitude larger than expected from electric field fluctuations due to thermal motion of electrons in the conductors. This effect, known as anomalous heating, is not fully understood. One of the open questions is the heating rate's dependence on the ion-electrode separation. We present a direct measurement of this dependence in an ion trap of simple planar geometry. The heating rates are determined by taking images of a single ^{172}Yb^{+} ion's resonance fluorescence after a variable heating time and deducing the trapped ion's temperature from measuring its average oscillation amplitude. Assuming a power law for the heating rate versus ion-surface separation dependence, an exponent of -3.79±0.12 is measured.