Karl Franzens University Graz
Graz University of Technology
|
|
| |
Karl Franzens University Graz | Graz University of Technology | |
Trapping and Interfacing Cold Neutral Atoms Using Optical Nanofibers We recently demonstrated a new experimental platform for trapping and optically interfacing laser-cooled cesium atoms [1]. The scheme uses a two-color evanescent field surrounding an optical nanofiber to localize the atoms in a one-dimensional optical lattice 200 nm above the nanofiber surface. At the same time, the atoms are efficiently interrogated with light which is sent through the nanofiber. Remarkably, an ensemble of 2000 trapped atoms yields an optical depth of up to 32, equivalent to 1.6 % absorbance per atom. Moreover, when dispersively interfacing the atoms, we observe ~ 1 mrad phase shift per atom at a detuning of six times the natural linewidth [2]. Our technique provides unprecedented ease of access for the coherent optical manipulation of trapped neutral atoms and opens the route towards the direct integration of atomic ensembles into fiber networks, an important prerequisite for large scale quantum communication. Moreover, our nanofiber trap is ideally suited to the realization of hybrid quantum systems combining atoms with solid state quantum devices. Finally, the use of nanofibers for atom trapping allows one to straightforwardly realize interesting trapping geometries which are not easily accessible with freely propagating laser beams. |