High-Resolution Tunneling Spectroscopy of Fractional Quantum Hall States

Yuwen Hu; Yen-Chen Tsui; Minhao He; Umut Kamber; Taige Wang; Amir S. Mohammadi; Kenji Watanabe; Takashi Taniguchi; Zlatko Papic; Michael P. Zaletel; Ali Yazdani

doi:10.1038/s41567-025-02830-y

arXiv · 2308.05789

High-Resolution Tunneling Spectroscopy of Fractional Quantum Hall States

Yuwen Hu·Yen-Chen Tsui·Minhao He·Umut Kamber·Taige Wang·Amir S. Mohammadi·Kenji Watanabe·Takashi Taniguchi·Zlatko Papic·Michael P. Zaletel·Ali Yazdani

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Abstract

Strong interaction between electrons in two-dimensional systems in the presence of a high magnetic field gives rise to fractional quantum Hall states that host quasiparticles with fractional charge and fractional exchange statistics. Here, we demonstrate high-resolution scanning tunneling microscopy and spectroscopy of fractional quantum Hall states in ultra clean Bernal-stacked bilayer graphene devices. Spectroscopy measurements show sharp excitations that have been predicted to emerge when electrons fractionalize into bound states of quasiparticles. We find energy gaps for candidate non-abelian fractional states that are larger by a factor of five than other related systems - for example semiconductor heterostructures - and this suggests bilayer graphene is an ideal platform for the manipulation of these quasiparticles and for the creation of a topological quantum bit. We also find previously unobserved fractional states in our very clean graphene samples.

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Yuwen Hu, Yen-Chen Tsui, Minhao He, Umut Kamber, Taige Wang, Amir S. Mohammadi, Kenji Watanabe, Takashi Taniguchi, Zlatko Papic, Michael P. Zaletel, Ali Yazdani. 2023-08-10. High-Resolution Tunneling Spectroscopy of Fractional Quantum Hall States. https://doi.org/10.1038/s41567-025-02830-y

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