Single photon emission with controlled waveform demonstrated for the first time

 Single photons exhibit quantum mechanical properties, such as superposition and no-cloning character. These properties supply the basis for the use of single photos as an ideal carrier of quantum information. Special schemes are necessary for generating single photons with a fixed temporal spacing, since they tend to bunch together, or appear randomly even when a laser is used. A single calcium ion 40Ca+ trapped and cooled in an ion trap has been used to generate single photons with fixed timing as well as controlled waveform for the first time, in collaboration with Prof. Herbert Walther's group at Max-Planck Institute of Quantum Optics in Germany. Stimulated Raman scattering by cavity is the mechanism of this achievement. This single-photon emission process can be extended to a basic quantum mechanical protocol of mapping quantum states between ions and photons. The protocol might supply a crucial building block for quantum networks which connect quantum computers, and synchronize quantum atomic clocks securing network transactions.