277 citations · 1k across the 27 of their papers we have counts for
28 papers
Performance optimization of cascaded traveling wave Josephson parametric amplifiers
Ilari Lilja, Ekaterina Mukhanova, Stanislav Khaldeev +3
Traveling-wave parametric amplifiers (TWPAs) based on Josephson metamaterials provide broadband gain with near-quantum-limited added noise. Whereas long nonlinear metamaterial devi…
Phase-sensitive cascade quantum amplifier with nearly noiseless operation
Ilari Lilja, Ekaterina Mukhanova, Michael Perelshtein +5
Phase-sensitive parametric devices enable quadrature-selective amplification with the potential for sub-quantum-limited noise performance. In this work, we investigate the operatio…
Native-oxide-passivated trilayer junctions for superconducting qubits
Pankaj Sethi, Om Prakash, Jukka-Pekka Kaikkonen +15
Superconducting qubits in today's quantum processing units are typically fabricated with angle-evaporated aluminum--aluminum-oxide--aluminum Josephson junctions. However, there is…
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…
Correlation measurement of propagating microwave photons at millikelvin
Aarne Keränen, Qi-Ming Chen, András Gunyhó +5
Microwave photons are important carriers of quantum information in many promising platforms for quantum computing. They can be routinely generated, controlled, and teleported in ex…
Near-ground state cooling in electromechanics using measurement-based feedback and Josephson parametric amplifier
Ewa Rej, Richa Cutting, Debopam Datta +5
Feedback-based control of nano- and micromechanical resonators can enable the study of macroscopic quantum phenomena and also sensitive force measurements. Here, we demonstrate the…
Single-Shot Readout of a Superconducting Qubit Using a Thermal Detector
András M. Gunyhó, Suman Kundu, Jian Ma +8
Measuring the state of qubits is one of the fundamental operations of a quantum computer. Currently, state-of-the-art high-fidelity single-shot readout of superconducting qubits re…
Generation and structuring of multipartite entanglement in Josephson parametric system
K. V. Petrovnin, M. R. Perelshtein, T. Korkalainen +4
Quantum correlations are a vital resource in advanced information processing based on quantum phenomena. Remarkably, the vacuum state of a quantum field may act as a key element fo…
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…
Broadband continuous variable entanglement generation using Kerr-free Josephson metamaterial
Michael Perelshtein, Kirill Petrovnin, Visa Vesterinen +13
Entangled microwave photons form a fundamental resource for quantum information processing and sensing with continuous variables. We use a low-loss Josephson metamaterial comprisin…
Microwave response of a metallic superconductor subject to a high-voltage gate electrode
Giacomo Catto, Wei Liu, Suman Kundu +3
Processes that lead to the critical-current suppression and change of impedance of a superconductor under the application of an external voltage is an active area of research, espe…
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…
A superconductor free of quasiparticles for seconds
E. T. Mannila, P. Samuelsson, S. Simbierowicz +6
Superconducting devices, based on the Cooper pairing of electrons, play an important role in existing and emergent technologies, ranging from radiation detectors to quantum compute…
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…
Bolometer operating at the threshold for circuit quantum electrodynamics
R. Kokkoniemi, J. -P. Girard, D. Hazra +7
Radiation sensors based on the heating effect of the absorbed radiation are typically relatively simple to operate and flexible in terms of the input frequency. Consequently, they…
Fast control of dissipation in a superconducting resonator
Vasilii Sevriuk, Kuan Yen Tan, Eric Hyyppä +8
We report on fast tunability of an electromagnetic environment coupled to a superconducting coplanar waveguide resonator. Namely, we utilize a recently-developed quantum-circuit re…
Optimized heat transfer at exceptional points in quantum circuits
Matti Partanen, Jan Goetz, Kuan Yen Tan +12
Superconducting quantum circuits are potential candidates to realize a large-scale quantum computer. The envisioned large density of integrated components, however, requires a prop…
Magnetic field sensing with the kinetic inductance of a high- superconductor
V. Vesterinen, S. Ruffieux, A. Kalabukhov +5
We carry out an experimental feasibility study of a magnetic field sensor based on the kinetic inductance of the high- superconductor yttrium barium copper oxide. We…
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…
Nanobolometer with Ultralow Noise Equivalent Power
R. Kokkoniemi, J. Govenius, V. Vesterinen +10
Since the introduction of bolometers more than a century ago, they have been applied in a broad spectrum of contexts ranging from security and the construction industry to particle…
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…
Flux-tunable heat sink for quantum electric circuits
Matti Partanen, Kuan Yen Tan, Shumpei Masuda +10
Superconducting microwave circuits show great potential for practical quantum technological applications such as quantum information processing. However, fast and on-demand initial…
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…
Detecting bit-flip errors in a logical qubit using stabilizer measurements
D. Ristè, S. Poletto, M. -Z. Huang +4
Quantum data is susceptible to decoherence induced by the environment and to errors in the hardware processing it. A future fault-tolerant quantum computer will use quantum error c…