9,235 research outputs found
Engineering fast and stable splitting of matter waves
When attempting to split coherent cold atom clouds or a Bose-Einstein
condensate (BEC) by bifurcation of the trap into a double well, slow adiabatic
following is unstable with respect to any slight asymmetry, and the wave
"collapses" to the lower well, whereas a generic fast chopping splits the wave
but it also excites it. Shortcuts to adiabaticity engineered to speed up the
adiabatic process through non-adiabatic transients, provide instead quiet and
robust fast splitting. The non-linearity of the BEC makes the proposed shortcut
even more stable
Optimal trajectories for efficient atomic transport without final excitation
We design optimal harmonic-trap trajectories to transport cold atoms without
final excitation, combining an inverse engineering techniqe based on
Lewis-Riesenfeld invariants with optimal control theory. Since actual traps are
not really harmonic, we keep the relative displacement between the center of
mass and the trap center bounded. Under this constraint, optimal protocols are
found according to different physical criteria. The minimum time solution has a
"bang-bang" form, and the minimum displacement solution is of "bang-off-bang"
form. The optimal trajectories for minimizing the transient energy are also
discussed.Comment: 10 pages, 7 figure
Fast shuttling of a trapped ion in the presence of noise
We theoretically investigate the motional excitation of a single ion caused
by spring-constant and position uctuations of a harmonic trap during trap
shuttling processes. A detailed study of the sensitivity on noise for several
transport protocols and noise spectra is provided. The effect of slow
spring-constant drifts is also analyzed. Trap trajectories that minimize the
excitation are designed combining invariant-based inverse engineering,
perturbation theory, and optimal control
- …