報告題目：Experimental realization of a topologically protected Hadamard gate via braiding Fibonacci anyons
報告人：萬義頓 教授 復旦大學
報告時間：2023年4月8號（星期六）下午15:00
報告地點：LE201
邀請人：胡自翔
報告摘要： Topological quantum computation (TQC) is one of the most striking architectures that can realize fault-tolerant quantum computers. In TQC, the logical space and the quantum gates are topologically protected, i.e., robust against local disturbances. The topological protection, however, requires rather complicated lattice models and hard-to-manipulate dynamics; even the simplest system that can realize universal TQC--the Fibonacci anyon system--lacks a physical realization, let alone braiding the non-Abelian anyons. Here, we propose a disk model that can realize the Fibonacci-anyon system and construct the topologically protected logical spaces with the Fibonacci anyons. Via braiding the Fibonacci anyons, we can implement universal quantum gates on the logical space. Our disk model merely requires 2 physical qubits to realize 3 Fibonacci anyons at the boundary, and then by 15 sequential braiding operations to construct a topologically protected Hadamard gate, which is to date the least-resource requirement for TQC. To showcase, we implement a topological Hadamard gate with 2 nuclear spin qubits, which reaches 97.18% fidelity by randomized benchmarking. We further prove by experiment that the logical space and Hadamard gate are topologically protected: local disturbances due to thermal fluctuations result in a global phase only. As a platform-independent proposal, our work is a proof of principle of TQC and paves the way towards fault-tolerant quantum computation.
報告人介紹：萬義頓，復旦大學物理系教授，華南理工大學計算機與經濟學雙學士（1998）、美國賓夕法尼亞大學計算機碩士（2002）、加拿大渥太華大學物理碩士（2004）、加拿大滑鐵盧大學暨圓周理論物理研究所理論物理博士（2009），于日本近畿大學、東京大學、加拿大圓周理論物理研究所做博士后，2016年加入復旦物理系，從事拓撲物態、量子信息與計算、量子引力等領域的交叉研究。
