By Jürgen Appel, University of Copenhagen
In the search for systems suitable for implementing light-matter quantum interfaces the interaction achieved with guided photons has emerged as one of the most prospective candidates. Efficient coupling of guided photons has been achieved with such different systems as atoms or quantum dots coupled to photonic bandgap waveguides or atoms in a hollow core fiber.
In our setup, we trap two strings of atoms in the evanescent field of a tapered optical fiber (TOF) so that they are strongly coupled to the single guided photonic fiber mode. We present 12% coherent Bragg scattering off such a one-dimensional system of approx. 1000 atoms, realized by modulating the light-atom interaction by mechanical motion. We investigate the inhomogeneous coupling of the thermal ensemble, evaluate its importance for quantum technology applications and present tools to operate in its presence to perform tasks such as state tomography and spin squeezing.