QUROPE Quantum Information Processing and Communication in Europe

Using modern micro- and nano-fabrication techniques combined with superconducting materials we realize quantum electronic circuits to create, store, and manipulate individual microwave photons on a chip. The strong interaction of photons with superconducting quantum two-level systems allows us to probe the fundamental quantum properties of light. In particular, I will discuss experiments in which we realize an on-demand microwave frequency single photon source which we characterize by correlation function measurements.

The fields of semiconductor quantum dots and superconducting circuits have both moved forward at a remarkable pace in the last 5 years, with both quantum technologies now holding great promise for practical quantum information processing (QIP). The concept of circuit quantum electrodynamics (QED), in which qubits are coupled to single microwave photons in a superconducting resonator has enabled much recent progress with superconducting circuits, and is a promising architecture for strong coupling cavity QED and QIP with a variety of other qubit systems.

Teleportation of a quantum state may be used for distributing entanglement between distant qubits in quantum communication and for realizing universal and fault-tolerant quantum computation. Here we demonstrate the implementation of a teleportation protocol, up to the single-shot measurement step, with superconducting qubits coupled to a microwave resonator. Using full quantum state tomography and evaluating an entanglement witness, we show that the protocol generates a genuine tripartite entangled state of all three-qubits.