报告摘要 | Fractional quantum Hall effect (FQHE) is a prime example of topological quantum many-body phenomena, arising from the interplay between strong electron correlation, topological order, and time reversal symmetry breaking. Recently, a lattice analog of FQHE at zero magnetic field has been observed, confirming the existence of a zero-field fractional Chern insulator (FCI). Despite this, the bulk-edge correspondence -- a hallmark of FCI featuring an insulating bulk with conductive edges -- has not been directly observed. In fact, this correspondence has not been visualized in any system for fractional states due to experimental challenges. In this talk, I will discuss the imaging of FCI edge states in twisted MoTe2 by employing a newly developed modality of microwave-impedance microscopy. I will show how local measurement further reveals tantalizing prospects of neighboring domains with different fractional orders. These findings pave the way for research into topologically protected 1D interfaces between various anyonic states at zero magnetic field, such as topological entanglement entropy, Halperin-Laughlin interfaces, and the creation of non-abelian anyons. Besides, I will also present some local sensing results of excitonic responses using the same technique, and how it enables excitons to be used as local quantum sensors for electrometry. References:
[1] Zhurun Ji, Mark Barber, Ziyan Zhu, Carlos Kometter, Jiachen Yu, Mengkun Liu, Thomas Devereaux, Ben Feldman, Zhixun Shen, “Local Probing of Excitonic Responses and Deep Learning-Enhanced Field Sensing”, arXiv:2311.04211 [2] Zhurun Ji*, Heonjoon Park*, Mark E Barber, Chaowei Hu, Kenji Watanabe, Takashi Taniguchi, Jiun-Haw Chu, Xiaodong Xu, Zhi-xun Shen, “Local probe of bulk and edge states in a fractional Chern insulator”, Nature, 635, 578–583 (2024) |
