Laser controlled tunneling in a vertical optical lattice

TL;DR

This paper demonstrates laser-controlled tunneling in a vertical optical lattice, enabling coherent manipulation of atomic states for potential applications in quantum information processing.

Contribution

It introduces a spectroscopic method to control tunneling between lattice sites using Raman lasers, advancing coherent manipulation techniques for cold atoms.

Findings

Successful preparation of superpositions of Wannier Stark states

Measurement of coherence times via spatial interferometry

Controlled tunneling matching Bloch frequency multiples

Abstract

Raman laser pulses are used to induce coherent tunnelling between neighbouring sites of a vertical 1D optical lattice. Such tunneling occurs when the detuning of a probe laser from the atomic transition frequency matches multiples of the Bloch frequency, allowing for a spectroscopic control of the coupling between Wannier Stark (WS) states. In particular, we prepare coherent superpositions of WS states of adjacent sites, and investigate the coherence time of these superpositions by realizing a spatial interferometer. This scheme provides a powerful tool for coherent manipulation of external degrees of freedom of cold atoms, which is a key issue for quantum information processing.