Título: Superconducting qubits and quantum non-demolition measurement

Dr. Olivier Buisson (Université Grenoble Alpes/Institut Néel) 

Resumo: During the last decade, it has been demonstrated that superconducting Josephson quantum circuits constitute ideal blocks to realize quantum mechanical experiments and to build promising quantum bits for quantum information processing. These circuits appear as artificial atoms whose properties are fixed by electronics compounds (capacitance, inductance, tunnel barrier). The presentation will first introduce the superconducting transmon qubits which is the most used. Their strengths and weaknesses and some current issues will be commented. In a second part, we will focus on quantum measurement of transmon qubit. In particular we will discuss the fidelity and Quantum Non-Demolition of the measurement. We will present a novel scheme that we developed in Grenoble based on non-perturbative Cross-Kerr coupling which overcomes the usual limitations.