Abstract
Quantum materials exhibit dissipationless topological edge state transport with quantized Hall conductance, offering notable potential for fault-tolerant computing technologies. However, the development of topological edge state-based computing devices remains a challenge. Here we report the selective and quasi-continuous ferroelectric switching of topological Chern insulator devices, showcasing a proof-of-concept demonstration in noise-immune neuromorphic computing. We fabricate this ferroelectric Chern insulator device by encapsulating magic-angle twisted bilayer graphene with doubly aligned h-BN layers and observe the coexistence of the interfacial ferroelectricity and the topological Chern insulating states. The observed ferroelectricity exhibits an anisotropic dependence on the in-plane magnetic field. By tuning the amplitude of the gate voltage pulses, we achieve ferroelectric switching between any pair of Chern insulating states in the presence of a finite magnetic field, resulting in 1,280 ferroelectric states with distinguishable Hall resistance levels on a single device. Furthermore, we demonstrate deterministic switching between two arbitrary levels among the record-high number of ferroelectric states. This unique switching capability enables the implementation of a convolutional neural network resistant to external noise, utilizing the quantized Hall conductance levels of the Chern insulator device as weights. Our study provides a promising avenue towards the development of topological quantum neuromorphic computing, where functionality and performance can be drastically enhanced by topological quantum materials.
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The data that support the plots within this paper and other findings of this study are available in the supplementary data files. All source data can be acquired from the corresponding authors upon request. Source data are provided with this paper.
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Acknowledgements
This work was supported in part by the National Key R and D Program of China under grant 2023YFF1203600 (S.-J.L.), the National Natural Science Foundation of China (12322407 (B.C.), 62122036 (S.-J.L.), 62034004 (F.M.), 61921005 (F.M.) and 12074176 (B.C.)), the National Key R&D Program of China under grant 2023YFF0718400 (B.C.), the Leading-edge Technology Program of Jiangsu Natural Science Foundation BK20232004 (F.M.), the Strategic Priority Research Program of the Chinese Academy of Sciences XDB44000000 (F.M.) and the Innovation Program for Quantum Science and Technology (F.M.). F.M. and S.-J.L. acknowledge support from the AIQ Foundation and the e-Science Center of Collaborative Innovation Center of Advanced Microstructures. The microfabrication centre of the National Laboratory of Solid State Microstructures (NLSSM) is also acknowledged for their technical support. We thank J. Liu and L. Yang for fruitful discussions.
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F.M., B.C. S.-J.L. and M.C. conceived the idea and designed the experiments. F.M., B.C. and S.-J.L. supervised the whole project. Y.X. and M.C. fabricated the devices. M.C. performed the measurements. Z.Y. and M.C. conducted the neural network simulation. M.C., F.C., Q.L. and J.X. provided assistance in the experiments. X.-Z.L. and W.-Y.H. provided a phenomenological model of magnetoelectric effect. M.W. provided a sliding-ferroelectric model. T.T. and K.W. provided h-BN samples. M.C., B.C., S.-J.L. and F.M. co-wrote the manuscript.
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Nature Nanotechnology thanks Jihang Zhu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Supplementary Figs. 1–16, discussion, Tables 1 and 2, and Sections 1–10.
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Chen, M., Xie, Y., Cheng, B. et al. Selective and quasi-continuous switching of ferroelectric Chern insulator devices for neuromorphic computing. Nat. Nanotechnol. (2024). https://doi.org/10.1038/s41565-024-01698-y
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DOI: https://doi.org/10.1038/s41565-024-01698-y
