Experimental studies of fast ion transport outside adiabatic limits are very important for a future ion trap quantum computer as it will spend approximately 99% of time shuttling ions around. It is therefore crucial to understand and be able to control the process of fast (nonadiabatic) ion transport such that the computationall timescale does not exceed the coherence time of the quantum register. 

We investigate theoretically and experimentally the excitation of oscillations from fast ion transports with error-function voltage ramps. Nonadiabatic transports during only four oscillation periods (20µs for 4mm) are performed with over 99% success probability and adiabatic transports (500µs) with over 99.8% success probability. The transport induced ion excitation is measured in good agreement with a simple classical model [1].

The time after switching on the Doppler cooling laser after the transport, until the ion is re-coold again and scatters light, is a measure of its motional excitation. In the figure you see that this recover time increases if the transport was very fast.

[1] G. Huber, Th. Deuschle, W. Schnitzler, R. Reichle, K. Singer and F. Schmidt-Kaler, New Journal of Physics accepted (2007). arXiv:0711.2947