Several Schemes For Quantuam Information Based On Superconducting Josephson Junction

Quantum information (QI) have been widely studied in recent years.As one of the most important characters of the QI, quantum entanglementhave attracted much attention and various of entanglement states havebeen proposed. Meanwhile, superconductive josephson junction is one ofthe most promising candidate of the quantum computer, because it hasmany merits, such as scalability. Based on the development of thesuperconducting qubit, we propose several effective methods toimplement some entanglement states and quantum logical gates. Thispaper mainly contains the following aspects:1. By using different system, we implement some useful entanglementstates such as χ-Typeentanglement state, GHZ state, W state andcoherent entanglement state.2. The quantum information exchange between two charge qubits havebeen achieved using two-photon sideband transition.3. We propose an effective method to implement the1â†'N controlledphase gate of transmon qubits in Circuit QED.