120 citations · 1.2k across the 44 of their papers we have counts for
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Effect of ion irradiation on superconducting thin films
Katja Kohopää, Alberto Ronzani, Robab Najafi Jabdaraghi +8
We demonstrate ion irradiation by argon or gallium as a wafer-scale post-processing method to increase disorder in superconducting thin films. We study several widely used supercon…
Cascaded superconducting junction refrigerators: optimization and performance limits
A. Kemppinen, A. Ronzani, E. Mykkänen +3
We demonstrate highly transparent silicon-vanadium and silicon-aluminum tunnel junctions with relatively low sub-gap leakage current and discuss how a trade-off typically encounter…
Flux-driven Josephson parametric amplifier for sub-GHz frequencies fabricated with side-wall passivated spacer junction technology
Slawomir Simbierowicz, Visa Vesterinen, Leif Grönberg +3
We present experimental results on a Josephson parametric amplifier tailored for readout of ultra-sensitive thermal microwave detectors. In particular, we discuss the impact of fab…
Side-wall spacer passivated sub-um Josephson junction fabrication process
Leif Grönberg, Mikko Kiviranta, Visa Vesterinen +5
We present a structure and a fabrication method for superconducting tunnel junctions down to the dimensions of 200 nm using i-line UV lithography. The key element is a side-wall-pa…
Dielectric losses in multi-layer Josephson junction qubits
David Gunnarsson, Juha-Matti Pirkkalainen, Jian Li +4
We have measured the excited state lifetimes in Josephson junction phase and transmon qubits, all of which were fabricated with the same scalable multi-layer process. We have compa…