标题： 间隙双层石墨烯中非局域输运的边缘依赖性 显示英文标题

标题： Edge dependece of nonlocal transport in gapped bilayer graphene

摘要： 有间隙石墨烯的拓扑性质已被探索用于谷电子学应用。 先前的输运实验通过霍尔条器件中的大非局部电阻表明了其拓扑性质，但这种电阻的来源尚不清楚。 本研究聚焦于具有自然剥离边缘的双栅双层石墨烯（BLG）器件，研究了氧等离子体工艺对边缘蚀刻如何影响电子输运。 蚀刻前，电荷中性点的局部电阻随位移场呈指数增长，而非局部电阻可通过欧姆贡献很好地解释，这是一般有间隙BLG的典型特征。 然而，蚀刻后，局部电阻随着位移场的增加而饱和，而非局部电阻与欧姆贡献相差三个数量级。 我们认为局部和非局部电阻的这些显著变化是由于边缘蚀刻后形成了边缘导电路径，而不是之前文献中所声称的有间隙BLG的拓扑性质。 显示英文摘要

摘要： The topological properties of gapped graphene have been explored for valleytronics applications. Prior transport experiments indicated their topological nature through large nonlocal resistance in Hall-bar devices, but the origin of this resistance was unclear. This study focused on dual-gate bilayer graphene (BLG) devices with naturally cleaved edges, examining how edge-etching with an oxygen plasma process affects electron transport. Before etching, local resistance at the charge neutral point increased exponentially with the displacement field and nonlocal resistance was well explained by ohmic contribution, which is typical of gapped BLG. After-etching, however, local resistance saturated with increasing displacement field, and nonlocal resistance deviated by three orders of magnitude from ohmic contribution. We suggest that these significant changes in local and nonlocal resistance arise from the formation of edge conducting pathways after the edge-etching, rather than from a topological property of gapped BLG that has been claimed in previous literatures.