Yoshiki Sunada

All Publications

• Dissipation and noise in strongly driven Josephson junctions SCIPOST PHYSICS CORE Vadimov, V., Sunada, Y., Mottonen, M. 2025; 8 (4)

  View details for DOI 10.21468/SciPostPhysCore.8.4.065

  View details for Web of Science ID 001588658200001

• Methods to achieve near-millisecond energy relaxation and dephasing times for a superconducting transmon qubit NATURE COMMUNICATIONS Tuokkola, M., Sunada, Y., Kivijarvi, H., Albanese, J., Gronberg, L., Kaikkonen, J., Vesterinen, V., Govenius, J., Mottonen, M. 2025; 16 (1): 5421

  Abstract

  Superconducting qubits are one of the most promising physical systems for implementing quantum computers. However, executing quantum algorithms of practical computational advantage requires further improvements in the fidelities of qubit operations, which are currently limited by the energy relaxation and dephasing times of the qubits. Here, we report our measurement results of a high-coherence transmon qubit with energy relaxation and echo dephasing times surpassing those in the existing literature. We measure a qubit frequency of 2.9 GHz, an energy relaxation time T1 with a median of 425 μs and a maximum of (666 ± 33)μs, and an echo dephasing time T 2 echo with a median of 541 μs and a maximum of (1057 ± 138)μs. We report in detail our design, fabrication process, and measurement setup to facilitate the reproduction and wide adoption of high-coherence transmon qubits in the academia and industry.

  View details for DOI 10.1038/s41467-025-61126-0

  View details for Web of Science ID 001524916200017

  View details for PubMedID 40628722

  View details for PubMedCentralID PMC12238396

• Generation of Frequency-Tunable Shaped Single Microwave Photons Using a Fixed-Frequency Superconducting Qubit PRX QUANTUM Miyamura, T., Sunada, Y., Wang, Z., Ilves, J., Matsuura, K., Nakamura, Y. 2025; 6 (2)

  View details for DOI 10.1103/PRXQuantum.6.020347

  View details for Web of Science ID 001513730300001

• Fast Multiplexed Superconducting-Qubit Readout with Intrinsic Purcell Filtering Using a Multiconductor Transmission Line PRX QUANTUM Spring, P. A., Milanovic, L., Sunada, Y., Wang, S., van Loo, A. F., Tamate, S., Nakamura, Y. 2025; 6 (2)

  View details for DOI 10.1103/PRXQuantum.6.020345

  View details for Web of Science ID 001513732200001