Collective Edge Modes Near the Onset of a Graphene Quantum Spin Hall State
Collective Edge Modes Near the Onset of a Graphene Quantum Spin Hall State
复制标题
石墨烯量子自旋霍尔态开始附近的集体边缘模式
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
H. Fertig
中科院分区：
文献类型：
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作者：
G. Murthy;E. Shimshoni;H. Fertig
石墨烯受到一个强大的，倾斜的磁场表现出可调的倾斜角，归因于从倾斜的反铁磁（CAF）到铁磁（FM）体状态在填充因子为零的过渡的绝缘体-金属过渡。我们发展了一个理论描述的自旋和谷边缘纹理的两个阶段，并通过过渡的边缘模式的性质隐含的演变。特别是，我们表明，CAF有带隙的中性模式的散装，但支持带隙的带电边缘模式。在过渡到FM状态的充电的边缘模式变得无缝，并顺利连接到FM状态的螺旋边缘模式。可能的实验结果进行了讨论。
Graphene subject to a strong, tilted magnetic field exhibits an insulator-metal transition tunable by tilt-angle, attributed to the transition from a canted antiferromagnetic (CAF) to a ferromagnetic (FM) bulk state at filling factor zero. We develop a theoretical description for the spin and valley edge textures in the two phases, and the implied evolution in the nature of edge modes through the transition. In particular, we show that the CAF has gapless neutral modes in the bulk, but supports gapped charged edge modes. At the transition to the FM state the charged edge modes become gapless and are smoothly connected to the helical edge modes of the FM state. Possible experimental consequences are discussed.