报告时间：2026年7月14日上午10:00

报告地点：物质科研楼A309会议室    

报告人：  马希铮副研究员粤港澳大湾区量子科学中心

报告题目/Title:Converting qubit relaxation into erasures with a single fluxonium

摘要/Abstract:Qubits that experience predominantly erasure errors offer distinct advantages for fault-tolerant operation. Indeed, dual-rail encoded erasure qubits in superconducting cavities and transmons have demonstrated high-fidelity operations by converting physical-qubit relaxation into logical-qubit erasures, but this comes at the cost of increased hardware overhead and circuit complexity. Here, we address these limitations by realizing erasure conversion in a single fluxonium operated at zero flux, where the logical state is encoded in its |0⟩-|2⟩ subspace. A single, carefully engineered resonator provides both mid-circuit erasure detection and end-of-line (EOL) logical measurement. Post-selection on non-erasure outcomes results in more than four-fold increase of the logical lifetime, from 193 µs to 869 µs. Finally, we characterize measurement-induced logical dephasing as a function of measurement power and frequency, and infer that each erasure check contributes a negligible error of (3.7 ±0.2) ×10−4. These results represent an important step toward establishing integer-fluxonium as a promising, resource-efficient platform for erasure-based error mitigation, without requiring additional hardware.

报告人简介/Curriculum Vitae: 马希铮，粤港澳大湾区量子科学中心副研究员。2020年于美国科罗拉多大学博尔德分校获得博士学位，随后在阿里巴巴达摩院量子实验室开展研究工作，并于2024年加入粤港澳大湾区量子科学中心。马希铮长期从事基于超导量子电路的实验研究，主要研究方向包括基于超导电路的混合量子体系、新型超导比特的操控与扩展，以及擦除比特的构建及其在容错量子计算中的应用。迄今在Nature Physics，Nature Communications，Physical Review Letters等国际高水平学术期刊发表论文十余篇。