101 citations · 629 across the 22 of their papers we have counts for
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Methods to achieve near-millisecond energy relaxation and dephasing times for a superconducting transmon qubit
Mikko Tuokkola, Yoshiki Sunada, Heidi Kivijärvi +6
Superconducting qubits are one of the most promising physical systems for implementing quantum computers. However, executing quantum algorithms of practical computational advantage…
Signal crosstalk in a flip-chip quantum processor
Sandoko Kosen, Hang-Xi Li, Marcus Rommel +15
Quantum processors require a signal-delivery architecture with high addressability (low crosstalk) to ensure high performance already at the scale of dozens of qubits. Signal cross…
Experimentally verified, fast analytic and numerical design of superconducting resonators in flip-chip architectures
Hang-Xi Li, Daryoush Shiri, Sandoko Kosen +10
In superconducting quantum processors, the predictability of device parameters is of increasing importance as many labs scale up their systems to larger sizes in a 3D-integrated ar…
Initial experimental results on a superconducting-qubit reset based on photon-assisted quasiparticle tunneling
V. A. Sevriuk, W. Liu, J. Rönkkö +15
We present here our recent results on qubit reset scheme based on a quantum-circuit refrigerator (QCR). In particular, we use the photon-assisted quasiparticle tunneling through a…
Qubit-compatible substrates with superconducting through-silicon vias
K. Grigoras, N. Yurttagül, J. -P. Kaikkonen +21
We fabricate and characterize superconducting through-silicon vias and electrodes suitable for superconducting quantum processors. We measure internal quality factors of a million…
A low-noise on-chip coherent microwave source
Chengyu Yan, Juha Hassel, Visa Vesterinen +5
The scaleup of quantum computers operating in the microwave domain requires advanced control electronics, and the use of integrated components that operate at the temperature of th…
Characterizing cryogenic amplifiers with a matched temperature-variable noise source
Slawomir Simbierowicz, Visa Vesterinen, Joshua Milem +7
We present a cryogenic microwave noise source with a characteristic impedance of 50 , which can be installed in a coaxial line of a cryostat. The bath temperature of the noise s…
Photon-number-dependent effective Lamb shift
Arto Viitanen, Matti Silveri, Máté Jenei +8
The Lamb shift, an energy shift arising from the presence of the electromagnetic vacuum, has been observed in various quantum systems and established as the part of the energy shif…
Calibration of cryogenic amplification chains using normal-metal--insulator--superconductor junctions
Eric Hyyppä, Máté Jenei, Shumpei Masuda +7
Various applications of quantum devices call for an accurate calibration of cryogenic amplification chains. To this end, we present a convenient calibration scheme and use it to ac…
Qubit Measurement by Multichannel Driving
Joni Ikonen, Jan Goetz, Jesper Ilves +10
We theoretically propose and experimentally implement a method of measuring a qubit by driving it close to the frequency of a dispersively coupled bosonic mode. The separation of t…