[9p-N304-1~15] KS.2 Quantum Information Engineering Group

3:45 PM - 4:00 PM JST(6:45 AM - 7:00 AM UTC)

[9p-N304-9] Implementation of Multi-Round Repetition Code and Evaluation of Logical Error Rates in Fixed-frequency Transmon Qubits

〇Toshi Sumida¹, Nilton Filho², Kazuhisa Ogawa², Akinori Machino^1,2, Hidehisa Shiomi^1,2, Takafumi Miyanaga², Koichiro Ban², Ryo Matuda², Ryutaro Ohira¹, Shinichi Morisaka^1,2, Keisuke Koike³, Takefumi Miyoshi^1,2,3, Yoshinori Kurimoto¹, Yuuya Sugita¹, Yosuke Ito¹, Yasunari Suzuki⁴, Peter Spring⁴, Yutaka Tabuchi⁴, Shuhei Tamate⁴, Yasunobu Nakamura^4,5, Makoto Negoro^1,2 (1.QuEL, Inc., 2.Univ-Osaka, 3.etreesJapan, Inc., 4.Riken, 5.Univ-Tokyo)

Keywords:

Superconducting Qubit,Quantum Error Correction

Fixed-frequency transmon qubits offer the advantage of simplified control wiring, making them promising candidates for large-scale quantum computing systems. However, implementing CNOT gates in these systems requires microwave-only cross-resonance drives, inevitably causing crosstalk around the control qubits. To address these challenges, pulse-level optimization techniques such as spectator-aware scheduling and the insertion of dynamical decoupling are effective. In this study, we adopted these methods to implement multi-round measurements of a bit-flip repetition code with code distance 3, and compared the logical error rate per round to the average longitudinal relaxation times of the qubits. In this presentation, we report our findings along with future prospects.