近日，美国宾夕法尼亚州立大学的Jun Zhu及其研究团队取得一项新进展。经过不懈努力，他们揭示具有量子化电阻和拓扑开关的高温量子谷霍尔效应。相关研究成果已于2024年7月18日在国际权威学术期刊《科学》上发表。

该研究团队展示了扭结态下的宽电阻平台-伯纳尔双层石墨烯中量子谷霍尔效应的表现-量子化到零磁场下的预测值。平台电阻在高达50开尔文下都具有非常弱的温度依赖性，并在几十mV的直流偏置窗口内平坦。研究人员演示了拓扑控制开关的电气操作，其开/关比为200。这些结果证明了扭结态的鲁棒性和可调性，以及它在构建电子量子光学器件方面的前景。

据悉，拓扑绝缘体的边缘态可以用来探索低维和拓扑界面上出现的基础科学。然而，对于螺旋边缘态来说，实现鲁棒的电导量子化是具有挑战性的。

附：英文原文

Title: High-temperature quantum valley Hall effect with quantized resistance and a topological switch

Author: Ke Huang, Hailong Fu, Kenji Watanabe, Takashi Taniguchi, Jun Zhu

Issue&Volume: 2024-07-18

Abstract: 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. Here 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 mV. 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.

DOI: 10.1126/science.adj374

Source: https://www.science.org/doi/10.1126/science.adj3742