Single-atom transport in optical conveyor belts: Enhanced shortcuts-to-adiabaticity approach

TL;DR

This paper investigates fast, high-fidelity single-atom transport in a realistic three-dimensional optical conveyor belt using shortcuts to adiabaticity, demonstrating the enhanced method outperforms traditional approaches at most lattice depths.

Contribution

It extends the STA and eSTA methods to a realistic 3D anharmonic optical lattice system for atomic transport, providing practical insights for experimental implementations.

Findings

eSTA outperforms STA at most lattice depths

Transport fidelities are evaluated using numerical Schrödinger equation propagation

Results are relevant for future optical conveyor belt experiments

Abstract

Fast and nearly lossless atomic transport, enabled by moving the confining trap, is a prerequisite for many quantum-technology applications. While theoretical studies of this problem have heretofore focussed almost exclusively on simplified scenarios (one-dimensional systems, purely harmonic confining potentials, etc.), we investigate it here in the experimentally relevant setting of a moving optical lattice ({\em optical conveyor belt}). We model single-atom transport in this system by taking fully into account its three-dimensional, anharmonic confining potential. We do so using the established method of shortcuts to adiabaticity (STA), i.e. an inverse-engineering approach based on Lewis-Riesenfeld invariants, as well as its recently proposed modification known as {\em enhanced} STA (eSTA). By combining well-controlled, advanced analytical techniques and the numerical propagation of a time-dependent Schr\"{o}dinger equation using the Fourier split operator method, we evaluate atom-transport fidelities within both approaches. Being obtained for realistic choices of system parameters, our results are relevant for future experiments with optical conveyor belts. Moreover, they reveal that in the system at hand the eSTA method outperforms its STA counterpart for all but the lowest optical-lattice depths.