Lü Xiao-Long, Yang Jia-En, Xie Hang
College of Science, Guangxi University of Science and Technology, Liuzhou, Guangxi 545006, China.
College of Physics, Chongqing University, Chongqing 401331, China.
iScience. 2025 Aug 18;28(9):113354. doi: 10.1016/j.isci.2025.113354. eCollection 2025 Sep 19.
We study the topological phases and resonant tunneling in graphene with the fixed extrinsic Rashba effect. Our study demonstrates that the phase diagram in the space of the Haldane model and ferromagnetic exchange field exhibits a topological phase transition between the Chern numbers and . With the staggered potential, the phase diagram presents the richer topological phases that are characterized by the Chern numbers from to . In particular, the Chern number corresponds to six distinct helical edge states in zigzag graphene nanoribbon, containing the valley edge state and mixed edge state. Additionally, the Chern numbers correspond to four valley-polarized edge states. In the junction consisting of different chiral edge states, the transmission manifests many resonant peaks with a transmittance of about 1, originating from the backscattering and different loop currents. Our findings offer insights into the edge states with identical Chern numbers and their resonant tunneling.
我们研究了具有固定外禀 Rashba 效应的石墨烯中的拓扑相和共振隧穿。我们的研究表明，在 Haldane 模型和铁磁交换场空间中的相图展示了陈数 和 之间的拓扑相变。在交错势的情况下，相图呈现出更丰富的拓扑相，其特征是陈数从 到 。特别地，陈数 对应于锯齿形石墨烯纳米带中的六个不同的螺旋边缘态，包括谷边缘态和混合边缘态。此外，陈数 对应于四个谷极化边缘态。在由不同手性边缘态组成的结中，传输表现出许多透射率约为 1 的共振峰，这些共振峰源于背散射和不同的环流。我们的发现为具有相同陈数的边缘态及其共振隧穿提供了见解。
