Generation of Microwave Single Photons and Homodyne Tomography on a Chip

We show that flux-based qubits can be coupled to superconductive resonators by means of a quantum-optical Raman excitation scheme and utilized for the deterministic generation of propagating microwave single photons. We introduce also a microwave quantum homodyning technique that enables the detection of single photons and other weak signals, and full state reconstruction via quantum tomography, realizing linear optics on a chip. These generation and detection protocols are building blocks for the advent of quantum information processing in the field of circuit QED (M. Mariantoni {\em et al.} cond-mat/0509737) . We discuss further applications of these ideas to create multipartite nonclassical states of the electromagnetic field.