Abstract
Due to the ultimate 2D nature of electron transport, graphene layers have provided a unique platform to investigate and engineer various quantum transport phenomena. Here, I will overview our past and ongoing efforts in this direction. First, I will discuss how we tune interlayer coupling in graphene moiré systems to explore new moiré physics [1]. Second, we will demonstrate that the van der Waals (vdW) interaction with semiconducting transition metal dichalcogenides (TMDCs) can induce strong spin-orbit coupling in graphene while keeping the graphene’s excellent transport properties [2]. Lastly, we will discuss our on-going works on cavity-coupled graphene and show that vacuum fluctuations can strongly modify quantum-Hall transport in the system [3]. Financial supports from the MOST China (2020YFA0309600) and the UGC/RGC of Hong Kong SAR (AoE/P-701/20, C7037-22G, 17300020, 17300521, 17309722, and 17301424) are acknowledged.
References
[1] Y. Wang, H. Xue, X. Wang, K. Watanabe, T. Taniguchi, and D.-K. Ki*, Phys. Rev. Lett. 133, 186301 (2024).
[2] Q. Rao et al., Nat. Commun. 14, 6124 (2023).
[3] H. Xue et al., ArXiv e-prints, arXiv:2506.21409 (2025).
Dr. Dongkeun Ki is an Associate Professor of the Department of Physics at the University of Hong Kong (HKU). He received his B.S. and Ph.D. degrees in Physics from Pohang University of Science and Technology (POSTECH) in 2004 and 2010, respectively, after which he moved to University of Geneva in Switzerland for his postdoctoral research under the supervision of Prof. Alberto Morpurgo. Dr. Ki’s research mainly focuses on discovering and understanding new quantum transport phenomena in low-dimensional systems by engineering their electronic bands using various state-of-the-art nanofabrication techniques. Materials of interest span widely from 1D nanowire to 3D bulk that include 2D materials, topological materials, and artificially designed van der Waals heterostructures. Throughout the investigation, Dr. Ki aims to understand and learn to control the underlying physical processes, expand our view of electronic materials, and contribute to the development of the new device applications. Dr. Ki has published over 40 peer-reviewed papers in high-profile journals, such as Physical Review Letters, Science, Nature Physics, Nature Communications, Advanced Materials, Nano Letters, and more with h-index of 22 and total citation over 1800. (WoS)