演讲人：周游 [复旦大学]
时 间：16:00-18:00, Mar 31, 2026 (Tue)
地 点：RM S327, MMW Building
内容：
Measuring global quantum properties-such as the fidelity to complex multipartite states-is both an essential and experimentally challenging task. Classical shadow estimation offers favorable sample complexity, but typically relies on many-qubit circuits that are difficult to realize on current platforms. We propose the robust phase shadow scheme, a measurement framework based on random circuits with controlled-Z as the unique entangling gate type, tailored to architectures such as trapped ions and neutral atoms. Leveraging tensor diagrammatic reasoning, we rigorously analyze the induced circuit ensemble and show that phase shadows match the performance of full Clifford-based ones. Importantly, our approach supports a noise-robust extension via purely classical post-processing, enabling reliable estimation under gate-dependent noise where existing techniques often fail. Additionally, by exploiting structural properties of random stabilizer states, we design an efficient post-processing algorithm that resolves a key computational bottleneck in previous shadow protocols. Our results enhance the practicality of shadow-based techniques, providing a robust and scalable route for estimating global properties in noisy quantum systems.(arxiv2507.13237).
个人简介:
周游是复旦大学未来信息创新学院、电磁波信息科学教育部重点实验室副研究员，研究领域是量子信息与量子计算理论。 2014年本科毕业于浙江大学信电系，2019年于清华大学飞球直播
院获博士学位，曾在中国科大、哈佛大学、南洋理工大学从事研究。研究兴趣包括量子系统标定与错误抑制，量子模拟算法、量子纠缠与关联等，已在 Nature Physics、Physical Review Letters、PRX Quantum、npj Quantum Information 等期刊发表论文30余篇，并担任 Physical Review Letters 青年顾问（ECA）和亚洲量子信息大会（AQIS）程序委员会委员，主持国家自然科学基金面上项目、青年项目（C类）及上海市关键技术研发项目等。
