Quantum optics with circuit QED & SC circuits in Innsbruck

16 06/2014

Monday, 16 Jun. 2014, 11:15 - 12:00

Workgroup Brukner Group

Presenter: Gerhard Kirchmair
Host: Caslav Brukner
Where: IQOQI Seminar Room, 2nd Floor Boltzmanngasse 3, 1090 Vienna

The recent development of a 3D architecture for superconducting circuits has dramatically increased the coherence time of qubits and cavities. This allows us to enter new regimes in quantum optics with circuit QED systems and enabled us to develop new tools and techniques to manipulate the state of a microwave cavity.
Using a two-cavity/single-qubit system, we engineer an artificial Kerr medium that enters the single photon Kerr regime where the interaction strength between individual photons in the cavity exceeds the loss rate. We realize a Gedankenexperiment proposed by Yurke and Stoler, in which the collapse and revival of a coherent state and the creation of cat states can be observed.
With a similar system we demonstrate a protocol that deterministically maps a qubit state to a superposition of coherent states in a cavity. We extend this method to create multi-component Schrödinger cat states. These states include the four-component compass state that can be used to realize a quantum memory protected against spontaneous emission.
At the end of the talk I want to briefly present the research plans and two main research directions of the Superconducting Quantum Circuits group at IQOQI Innsbruck.