Description

2010/11/09, Dr. Pol Forn-Díaz

Place:  Sala de Seminarios del Departamento de Física Teórica e Historia de la Ciencia
Time: 12h.
Title: Physics beyond the rotating-wave approximation in superconducting quantum circuits

Abstract
Quantum effects in superconducting circuits have been a focus of intense study during the past years. Progress has been made to couple several superconducting quantum bits (qubits) to each other and to perform quantum gates between them. Coupling to on-chip superconducting resonators has also been achieved. This has opened the possibility of coupling remote qubits to each other using the resonator as a coupler. At the same time, coupling qubits to resonators allows studying the qubit-photon interaction to regimes of parameters unattainable in the experiments of cavity quantum electrodynamics (QED) in quantum optics. In this talk I will present the superconducting flux qubit in the context of circuit QED. A system consisting of a flux qubit very strongly coupled to an LC resonator will be presented. It will be shown that the magnitude of the coupling allows the observation of Bloch-Siegert shifts. These shifts correspond to energy corrections in the qubit and the photon beyond the rotating-wave approximation in the Jaynes-Cummings model.