5 papers
Systematic frequency-collision analysis of the cross-resonance gate outside the straddling regime
Shinichi Inoue, Shotaro Shirai, Shuhei Tamate +4
Frequency crowding remains a major obstacle to scaling fixed-frequency transmon processors. Among the widely used all-microwave two-qubit gates, the cross-resonance (CR) gate is pa…
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…
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…
Superconducting surface trap chips for microwave-driven trapped ions
Yuta Tsuchimoto, Ippei Nakamura, Shotaro Shirai +1
Microwave-driven trapped ion logic gates offer a promising avenue for advancing beyond laser-based logic operations. In future microwave-based operations, however, the joule heat p…