Quantum information processing with three qubits: programmable quantum processors

Full text: I will describe a programmable quantum device (quantum processor) which would allow us to simulate completely positive maps (i.e. quantum mechanical processes) on quantum systems. These processors have two registers, the data register and the program register. The data register is the quantum system on which the map (i.e. a specific dynamics) is going to be applied. In the program register the information about the dynamics is encoded. The virtue of this arrangement is that we do not have to build a different processor every time we want to realize a new map. (author)