Quantum optics of single atoms
HERBERT WALTHER · Fortschritte der Physik · 2004
Abstract The widely discussed applications in quantum information and quantum cryptography require radiation sources capable of producing a fixed number of photons. This paper reviews the work performed in our laboratory using the one‐atom maser or micromaser to produce these fields on demand. In order to achieve this goal the maser is operating under the condition of the so‐called trapping states. In this situation the field of the micromaser stabilises to a photon number state. In the second part of the paper a single photon source on the basis of a trapped ion will be described. The strong localization and position control available when an ion trap is combined with an optical cavity is a big step forward in producing a deterministic atom‐field coupling necessary for quantum information processing.