论文标题
双极混合单层双层石墨烯连接中的电子马赫 - 齐汉德干扰
Electronic Mach-Zehnder interference in a bipolar hybrid monolayer-bilayer graphene junction
论文作者
论文摘要
坚固的磁场中的石墨烯物质实现了一维量子厅通道，为研究电子干扰提供了独特的平台。在这里，使用Landauer-Büttiker形式主义以及紧密结合模型，我们研究了单极和双极单层单层双层石墨烯（MLG-BLG）连接中的量子大厅（QH）效应。我们发现，在双极状态下，由扶手椅MLG-BLG连接制成的大厅杆会导致山谷极化的边缘通道干扰，并可以操作完全可调的Mach-Zehnder（MZ）干涉仪设备。对电导振荡的条宽度和磁场依赖性的研究表明，此类结构中的MZ干扰可能会受到BLG区域第二层的（Zigzag）边缘终止的类型[BLG区域[由垂直二聚体或非二聚体原子组成]。我们的发现表明，这两个接口都表现出一组双组Aharonov-bohm干扰，其中一个在两个相对的山谷极极化边缘通道之间占主导地位，并导致大振幅电导振荡范围从0到$ 2 E^2 / h $。我们通过分析求解门控半无限MLG-BLG连接的狄拉克 - 韦尔方程来解释和分析我们的发现。
Graphene matter in a strong magnetic field, realizing one-dimensional quantum Hall channels, provides a unique platform for studying electron interference. Here, using the Landauer-Büttiker formalism along with the tight-binding model, we investigate the quantum Hall (QH) effects in unipolar and bipolar monolayer-bilayer graphene (MLG-BLG) junctions. We find that a Hall bar made of an armchair MLG-BLG junction in the bipolar regime results in valley-polarized edge-channel interferences and can operate a fully tunable Mach-Zehnder (MZ) interferometer device. Investigation of the bar-width and magnetic-field dependence of the conductance oscillations shows that the MZ interference in such structures can be drastically affected by the type of (zigzag) edge termination of the second layer in the BLG region [composed of vertical dimer or non-dimer atoms]. Our findings reveal that both interfaces exhibit a double set of Aharonov-Bohm interferences, with the one between two oppositely valley-polarized edge channels dominating and causing a large-amplitude conductance oscillation ranging from 0 to $ 2 e^2 / h$. We explain and analyze our findings by analytically solving the Dirac-Weyl equation for a gated semi-infinite MLG-BLG junction.
