Publications (10)
Tunable and Switchable Coupling Between Two Superconducting Resonators
A. Baust, E. Hoffmann, M. Haeberlein +16
We realize a device allowing for tunable and switchable coupling between two superconducting resonators mediated by an artificial atom. For the latter, we utilize a persistent curr…
Squeezing with a flux-driven Josephson parametric amplifier
L. Zhong, E. P. Menzel, R. Di Candia +12
Josephson parametric amplifiers (JPA) are promising devices for applications in circuit quantum electrodynamics (QED) and for studies on propagating quantum microwaves because of t…
Path Entanglement of Continuous-Variable Quantum Microwaves
E. P. Menzel, R. Di Candia, F. Deppe +13
Path entanglement constitutes an essential resource in quantum information and communication protocols. Here, we demonstrate frequency-degenerate entanglement between continuous-va…
Displacement of propagating squeezed microwave states
Kirill G. Fedorov, L. Zhong, S. Pogorzalek +16
Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays…
Photon Statistics of Propagating Thermal Microwaves
J. Goetz, S. Pogorzalek, F. Deppe +7
In experiments with superconducting quantum circuits, characterizing the photon statistics of propagating microwave fields is a fundamental task. We quantify the ph…
Quantum probe of an on-chip broadband interferometer for quantum microwave photonics
P. Eder, T. Ramos, J. Goetz +11
Quantum microwave photonics aims at generating, routing, and manipulating propagating quantum microwave fields in the spirit of optical photonics. To this end, the strong nonlinear…
Ultrastrong coupling in two-resonator circuit QED
A. Baust, E. Hoffmann, M. Haeberlein +17
We report on ultrastrong coupling between a superconducting flux qubit and a resonant mode of a system comprised of two superconducting coplanar stripline resonators coupled galvan…
Tunable coupling of transmission-line microwave resonators mediated by an rf SQUID
F. Wulschner, J. Goetz, F. R. Koessel +18
We realize tunable coupling between two superconducting transmission line resonators. The coupling is mediated by a non-hysteretic rf SQUID acting as a flux-tunable mutual inductan…
Finite-time quantum entanglement in propagating squeezed microwaves
Kirill G. Fedorov, S. Pogorzalek, U. Las Heras +13
Two-mode squeezing is a fascinating example of quantum entanglement manifested in cross-correlations of incompatible observables between two subsystems. At the same time, these sub…
Second-order decoherence mechanisms of a transmon qubit probed with thermal microwave states
J. Goetz, F. Deppe, P. Eder +9
Thermal microwave states are omnipresent noise sources in superconducting quantum circuits covering all relevant frequency regimes. We use them as a probe to identify three second-…