Shortcut loading atoms into an optical lattice

TL;DR

This paper introduces a rapid, optimized pulse sequence method for transferring ultra-cold atoms into specific bands of an optical lattice, enabling precise state preparation for quantum applications.

Contribution

The authors develop a novel shortcut technique that efficiently loads atoms into desired lattice bands with high fidelity, extending to multi-dimensional lattices and superposition states.

Findings

Achieved transfer times of a few microseconds.

Demonstrated high fidelity in preparing specific and superposition states.

Validated the method with experimental results matching theoretical predictions.

Abstract

We present an effective and fast (few microseconds) procedure for transferring ultra-cold atoms from the ground state in a harmonic trap into the desired bands of an optical lattice. Our shortcut method is a designed pulse sequence where the time duration and the interval in each step are fully optimized in order to maximize robustness and fidelity of the final state with respect to the target state. The atoms can be prepared in a single band with even or odd parity, and superposition states of different bands can be prepared and manipulated. Furthermore, we extend this idea to the case of two-dimensional or three-dimensional optical lattices where the energies of excited states are degenerate. We experimentally demonstrate various examples and show very good agreement with the theoretical model. Efficient shortcut methods will find applications in the preparation of quantum systems, in quantum information processing, in precise measurement and as a starting point to investigate dynamics in excited bands.