We investigate quantum beats in the arrival-time distribution of single photons from a single trapped 40Ca+ ion, revealing their fundamentally different physical origins in two distinct experimental situations: In a Λ-type level scheme the interference of two 854-nm absorption amplitudes suppresses and enhances the emission process of Raman-scattered 393-nm photons; in a V-type level scheme the interference of two 393-nm emission amplitudes causes a rotation of their dipole emission pattern resulting in a temporal modulation of the detected photons. For both cases we demonstrate coherent control over the quantum-beat phase through the phases of the atomic and photonic input states, which also allows controlled adjustment of the total photon detection efficiency.
@article{arxiv.1406.4049,
title = {Quantum interference in the absorption and emission of single photons by a single ion},
author = {Michael Schug and Christoph Kurz and Pascal Eich and Jan Huwer and Philipp Müller and Jürgen Eschner},
journal= {arXiv preprint arXiv:1406.4049},
year = {2014}
}