124 citations · 934 across the 29 of their papers we have counts for
30 papers
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…
Quantum SWAP gate realized with CZ and iSWAP gates in a superconducting architecture
Christian Križan, Janka Biznárová, Liangyu Chen +19
It is advantageous for any quantum processor to support different classes of two-qubit quantum logic gates when compiling quantum circuits, a property that is typically not seen wi…
Fast unconditional reset and leakage reduction in fixed-frequency transmon qubits
Liangyu Chen, Simon Pettersson Fors, Zixian Yan +24
The realization of fault-tolerant quantum computing requires the execution of quantum error-correction (QEC) schemes, to mitigate the fragile nature of qubits. In this context, to…
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…
Equivalence of flexible stripline and coaxial cables for superconducting qubit control and readout pulses
V. Y. Monarkha, S. Simbierowicz, M. Borrelli +11
We report a comparative study on microwave control lines for a transmon qubit using: (i) flexible stripline transmission lines, and (ii) semi-rigid coaxial cables. During each expe…
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…
Efficient electronic cooling above 2 K by niobium-based superconducting tunnel junctions
J. Hätinen, A. Ronzani, R. P. Loreto +15
Replacing the bulky cryoliquid-based cooling stages of cryoenabled instruments by chip-scale refrigeration is envisioned to disruptively reduce the system size similar to microproc…
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…
Cryogenic microwave link for quantum local area networks
W. K. Yam, M. Renger, S. Gandorfer +16
Scalable quantum information processing with superconducting circuits is expected to advance from individual processors located in single dilution refrigerators to more powerful di…
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…
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…
Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier
Liangyu Chen, Hang-Xi Li, Yong Lu +17
High-fidelity and rapid readout of a qubit state is key to quantum computing and communication, and it is a prerequisite for quantum error correction. We present a readout scheme f…
Propagating Quantum Microwaves: Towards Applications in Communication and Sensing
Mateo Casariego, Emmanuel Zambrini Cruzeiro, Stefano Gherardini +22
The field of propagating quantum microwaves has started to receive considerable attention in the past few years. Motivated at first by the lack of an efficient microwave-to-optical…
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…
Supporting quantum technologies with an ultra-low loss silicon photonics platform
Matteo Cherchi, Arijit Bera, Antti Kemppinen +9
Photonic integrated circuits (PICs) are expected to play a significant role in the ongoing second quantum revolution, thanks to their stability and scalability. Still, major upgrad…
Building Blocks of a Flip-Chip Integrated Superconducting Quantum Processor
Sandoko Kosen, Hang-Xi Li, Marcus Rommel +24
We have integrated single and coupled superconducting transmon qubits into flip-chip modules. Each module consists of two chips -- one quantum chip and one control chip -- that are…
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…
Cryogenic sensor enabling broad-band and traceable power measurements
J. -P. Girard, R. E. Lake, W. Liu +4
Recently, great progress has been made in the field of ultrasensitive microwave detectors, reaching even the threshold for utilization in circuit quantum electrodynamics. However,…
Driving a low critical current Josephson junction array with a mode-locked laser
J. Nissila, T. Fordell, K. Kohopaa +11
We demonstrate the operation of Josephson junction arrays (JJA) driven by optical pulses generated by a mode-locked laser and an optical time-division multiplexer. A commercial pho…
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…
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-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…
Quantum Gates for Propagating Microwave Photons
Roope Kokkoniemi, Tuomas Ollikainen, Russell E. Lake +6
We report a generic scheme to implement transmission-type quantum gates for propagating microwave photons, based on a sequence of lumped-element components on transmission lines. B…