Chen-Hsuan Hsu

In this seminar, I will present our recent work on domain wall networks in moiré bilayer systems under an interlayer bias. We developed a bosonized model for the correlated network [1,2], showing that electron-electron interactions can be tuned by interlayer bias, screening length, and dielectric environment [1]. Including electron-phonon coupling, we obtained phase diagrams that reveal density waves and superconductivity with electrically tunable transitions.

I will also discuss scattering operators that capture processes within the network. Certain processes lead to gapped bulk states with gapless edge modes [2], giving rise to (fractional) quantum anomalous Hall states with distinct spectroscopic and transport signatures. Our network models further connect to the quantum Hall effect [3], quantum anomalous Hall effect [2], and quantum spin Hall effect [4], providing a broad framework for topological and correlated states.

Finally, I will discuss the formation of a two-dimensional spin helix in the domain wall network in the presence of localized spins [5]. By tuning system parameters, we find that the system exhibits a magnon-induced singularity with potentially observable features. Overall, these results highlight the moiré domain wall network as a novel platform for realizing exotic electronic orders.

References:
[1] Hao-Chien Wang and Chen-Hsuan Hsu, 2D Mater. 11, 035007 (2024).
[2] Chen-Hsuan Hsu, Daniel Loss, and Jelena Klinovaja, Phys. Rev. B 108, L121409 (2023).
[3] Charles L. Kane et al., Phys. Rev. Lett. 88, 036401 (2002).
[4] Jelena Klinovaja and Yarolav Tserkovnyak, Phys. Rev. B 90, 115426 (2014).
[5] Yung-Yeh Chang, Kazuma Saito, and Chen-Hsuan Hsu, Phys. Rev. Research 7, L032066 (2025). 

Address:Institute of Physics, Academia Sinica, , Taiwan