Bulletin of the American Physical Society

Single Photon Kerr Effect in Circuit QED

Gerhard Kirchmair

Published Mar 6, 2014• 0 citations

Abstract

The recent development of a 3D architecture for superconducting circuits has dramatically increased the coherence time of qubits and cavities. This allows us to reach the single-photon Kerr regime in circuit QED, where the interaction strength between individual photons in a waveguide cavity exceeds the loss rate. Here, using a two-cavity/single-qubit system, we engineer an artificial Kerr medium that enters this regime and allows the observation of new quantum effects. We realize a Gedankenexperiment [1] proposed by Yurke and Stoler, in which the collapse and revival of a coherent state can be observed. During this evolution non-classical superpositions of coherent states, i.e. multi-component Schrodinger cat states, are formed. We visualize this evolution by measuring the Husimi Q-function and confirm the non-classical properties of these transient states by Wigner tomography.

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