报告人：黄万通 博士（卡尔斯鲁厄理工学院）
报告题目：Single Spin Resonance of Individual Atoms and Molecules on Surfaces
报告时间：2025年11月6日 下午3:00
报告地点：304楼4203会议室
报告摘要：
The design and control of individual spins at the atomic level holds great promise for miniaturized spintronics, quantum sensing, and quantum information processing. In this talk, I will begin by reviewing the first decade of electron spin resonance scanning tunneling microscopy (ESR-STM), a technique that enables coherent spin control with unprecedented energy resolution down to neV and sub-angstrom spatial precision.
I will then showcase a strategy for engineering molecular spin complexes with tailored quantum properties. Using STM tip manipulation, we coupled an iron phthalocyanine (FePc) molecule with a single Fe atom located beneath a benzene ring of the Pc ligand, forming an Fe(C6H6)-FePc complex. This mixed-spin (1, 1/2) quantum ferrimagnet exhibits strong exchange coupling that yields to a well-separated two-level system [1]. This new correlated ground state enables coherent spin control and strikingly enhances the spin lifetime (>1.5 μs) compared to conventional on-surface quantum systems. Moreover, this spin-engineering approach constitutes a general design principle for on-surface spins and can be extended to other phthalocyanine-based molecules [2].
To realize those systems as functional building blocks in quantum information processing, local control of their quantum properties is essential. I will show that the ESR frequency of FePc and Fe(C6H6)–FePc ferrimagnet complexes can be tuned via voltage-dependent shifts [3]. We identify a distinct mechanism of spin–electric coupling (SEC), mediated by a transport-mediated exchange bias acting on the molecule. Finally, I will demonstrate that complexes with a different spatial arrangement can function as spin switches on a surface. This proof-of-concept device enables reversible, switchable qubit-qubit interactions within a molecule-based quantum platform [4].
References
[1] W. Huang et al., Nat. Commun. 16, 5208 (2025).
[2] W. Huang et al., ACS Nano 19, 1, 1190–1197 (2025).
[3] P. Greule, W. Huang et al., under review, arXiv:2507.13699 (2025).
[4] W. Huang*, K. H. Au-Yeung* et al., Nat. Commun. 16, 8242 (2025). (*equal contribution)
个人简介 ：
黄万通，2014年毕业于南开大学物理学院，获物理学学士学位。2020年毕业于清华大学，获物理学博士学位。2021年－至今，在德国卡尔斯鲁厄理工学院物理系从事博士后研究。博士期间利用稀释制冷扫描隧道显微镜研究TaS2，NbSe2，FeSe等二维材料在极低温强磁场条件下的物性；博后期间参与搭建干式稀释制冷-电子自旋共振-扫描隧道显微镜（ESR-STM），用其研究单个原子，分子及其杂化物的磁性并构造量子比特，旨在提高单量子比特的自旋寿命和相干时间。
联系人：仲启刚 教授