Publications (43)
Probing the Tavis-Cummings level splitting with intermediate-scale superconducting circuits
Ping Yang, Jan David Brehm, Juha Leppäkangas +7
We demonstrate the local control of up to eight two-level systems interacting strongly with a microwave cavity. Following calibration, the frequency of each individual two-level sy…
Long-lived, radiation-suppressed superconducting quantum bit in a planar geometry
Martin Sandberg, Michael R. Vissers, Tom Ohki +4
We present a superconducting qubit design that is fabricated in a 2D geometry over a superconducting ground plane to enhance the lifetime. The qubit is coupled to a microstrip reso…
Transmon Qubit in a Magnetic Field: Evolution of Coherence and Transition Frequency
Andre Schneider, Tim Wolz, Marco Pfirrmann +4
We report on spectroscopic and time-domain measurements on a fixed-frequency concentric transmon qubit in an applied in-plane magnetic field to explore its limits of magnetic field…
Engineering the microwave to infrared noise photon flux for superconducting quantum systems
Sergey Danilin, João Barbosa, Michael Farage +6
Electromagnetic filtering is essential for the coherent control, operation and readout of superconducting quantum circuits at milliKelvin temperatures. The suppression of spurious…
Magnons at low excitations: Observation of incoherent coupling to a bath of two-level-systems
Marco Pfirrmann, Isabella Boventer, Andre Schneider +4
Collective magnetic excitation modes, magnons, can be coherently coupled to microwave photons in the single excitation limit. This allows for access to quantum properties of magnon…
Resonance inversion in a superconducting cavity coupled to artificial atoms and a microwave background
Juha Leppäkangas, Jan David Brehm, Ping Yang +4
We demonstrate how heating of an environment can invert the line shape of a driven cavity. We consider a superconducting coplanar cavity coupled to multiple artificial atoms. The m…