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Title: High-temperature quantum valley Hall effect with quantized resistance and a topological switch
Edge states of a topological insulator can be used to explore fundamental science emerging at the interface of low dimensionality and topology. Achieving a robust conductance quantization, however, has proven challenging for helical edge states. In this work, we show wide resistance plateaus in kink states—a manifestation of the quantum valley Hall effect in Bernal bilayer graphene—quantized to the predicted value at zero magnetic field. The plateau resistance has a very weak temperature dependence up to 50 kelvin and is flat within a dc bias window of tens of millivolts. We demonstrate the electrical operation of a topology-controlled switch with an on/off ratio of 200. These results demonstrate the robustness and tunability of the kink states and its promise in constructing electron quantum optics devices.  more » « less
Award ID(s):
1904986
PAR ID:
10652960
Author(s) / Creator(s):
 ;  ;  ;  ;  
Publisher / Repository:
American Association for the Advancement of Science
Date Published:
Journal Name:
Science
Volume:
385
Issue:
6709
ISSN:
0036-8075
Page Range / eLocation ID:
657 to 661
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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