Zippy harmonic oscillators

LT13019 AND LT13077 - How fast can one transport a particle in a harmonic well from one place to another and come to a dead stop? With precise control, the particle can be transported arbitrarily fast and still return to its initial quantum mechanical state. So far, most experiments have been performed adiabatically, on time-scales much longer than one oscillation period. Now two research groups have cooled trapped ions to their quantum mechanical ground state and transported them over hundreds of micrometers (10,000s of  times the extent of the particle wave packet), in as few as 5 oscillation cycles. The rapid acceleration leads to excitation during transport, but the experiments show that the deceleration can be controlled well enough to return the ions to their ground state. Besides exploring a new regime of quantum transport, this work also has practical implications: Some proposals for scaling quantum information processing with trapped ions require ion transport inside a complicated array structure. So far, transport durations were long compared to those of quantum logic operations on the ions. The recent diabatic experiments  put these time scales on the same level, thereby significantly reducing the processing overhead.