4 papers
High-fidelity all-microwave CZ gate with partial erasure-error detection via a transmon coupler
Shotaro Shirai, Shinichi Inoue, Shuhei Tamate +3
Entangling gates between neighboring physical qubits are essential for quantum error correction. Implementing them in an all-microwave manner simplifies signal routing and control…
High- membrane resonators using ultra-high-stress crystalline TiN films
Yuki Matsuyama, Shotaro Shirai, Ippei Nakamura +6
High-quality-factor () mechanical resonators are essential components for precise sensing and control of mechanical motion at a quantum level. While amorphous materials such as…
Search for Dark Photon Dark Matter with a Mass around 36.1 μeV Using a Frequency-tunable Cavity Controlled through a Coupled Superconducting Qubit
Kan Nakazono, Shion Chen, Hajime Fukuda +10
We report the results of a search for dark photon dark matter using a cavity that employs a transmon qubit as a frequency tuner. The tuning mechanism utilizes the energy level shif…
Enhancing Intrinsic Quality Factors Approaching 10 Million in Superconducting Planar Resonators via Spiral Geometry
Yusuke Tominaga, Shotaro Shirai, Yuji Hishida +2
This study investigates the use of spiral geometry in superconducting resonators to achieve high intrinsic quality factors, crucial for applications in quantum computation and quan…