Fast neutral-atom transport and transfer between optical tweezers
Cristina Cicali, Martino Calzavara, Eloisa Cuestas, Tommaso Calarco, Robert Zeier, Felix Motzoi
Abstract
We study the optimization of the transport and transfer of neutral atoms between optical tweezers, both critical steps in the implementation of quantum computers and simulators. We analyze four experimentally relevant pulse shapes (piecewise linear, piecewise quadratic, minimum jerk, and a combination of linear and minimum jerk), and we also develop a protocol using shortcuts-to-adiabaticity (STA) methods to crucially incorporate the time-dependent effects of static traps. By computing a measure of the final transport error and two measures of the heating during transport, we show that our proposed STA protocol comprehensively outperforms all the experimentally inspired pulses. After further optimizing the pulse shapes, we find a lower bound on the protocol duration, compatible with the time at which the vibrational excitations exceed half of the states hosted by the moving tweezer. This lower bound is at least eight times faster than the one reported in recent experiments, which highlights the importance of including and optimizing the transfer from and to static traps, which may be the largest bottleneck to speed. Finally, our STA results demonstrate that a modulation in the depth of the moving tweezer designed to time-dependently counteract the effect of the static traps is key to reducing errors and reducing the pulse duration. To motivate the implementation of our STA pulses in future experiments, we provide a simple analytical approximation for the moving-tweezer position and depth controls.