报告题目：Probing dynamics of non-Abelian fusion of Majorana zero modes

报告人：冯伟 副教授 （天津大学量子交叉研究中心）

报告时间：2023年10月08日（星期日）15：00-16：30

报告地点：北洋园校区 49 教 210 室（腾讯会议：516-8729-1333）

报告摘要：

The nonlocal nature of the Majorana zero modes (MZMs) and non-Abelian statistics obeyed provide an elegant paradigm of topological quantum computation. Probing the underlying non-Abelian statistics, via either braiding or fusion, is an essential step in identifying MZMs through experiments. In this talk, I will report results of real-time simulations for probing the non-Abelian fusion of a pair of Majorana zero modes (MZMs). The nontrivial fusion outcomes can be either a vacuum or an unpaired fermion, which reflect the underlying non-Abelian statistics. The two possible outcomes can cause different charge variations in a nearby probing quantum dot (QD), while the charge occupation in the dot is detected by a quantum point contact. We find that gradual fusion and gradual coupling of the MZMs to the QD (in nearly adiabatic switching-on limit) provide a simpler detection scheme than sudden coupling after fusion to infer the coexistence of two fusion outcomes, by measuring the occupation probability of the QD. For sudden coupling after fusion, we propose and analyze continuous weak measurement for the quantum oscillations ofthe QD occupancy. From the power spectrum of the measurement currents, one can identify the characteristic frequencies and infer thus the coexistence of the fusion outcomes.

报告人简介：

冯伟，2009年，北京师范大学物理系获学士学位；2014年，北京师范大学物理系获博士学位。2014年起，天津大学理学院工作。2018年-2019年，赴澳大利亚RMIT大学国家公派访问。研究方向主要包括量子测量、量子信息和量子计算。

参考文献：

[1] D. Aasen, M. Hell, R. Mishmash, A. Higginbotham, J. Danon, M. Leijnse, T. Jespersen, J. Folk, C. Marcus, K. Flensberg, and J. Alicea, Milestones Toward Majorana-Based Quantum Computing, Phys. Rev. X 6, 031016 (2016).

[2] J. F. Steiner and F. von Oppen, Readout of Majorana qubits, Phys. Rev. Research 2, 033255 (2020).

[3] T. Zhou, M. C. Dartiailh, K. Sardashti, J. E. Han, A. Matos-Abiague, J. Shabani, and I.  Zutic, Fusion of Majorana bound states with mini-gate control in two-dimensional systems, Nat. Commun. 13, 1738 (2022). 

[4] J. Bai, Q. Wang, L. Xu, W. Feng, and X.-Q. Li, Probing the non-Abelian fusion of a pair of Majorana zero modes, arXiv 2309.13566 (2023).