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石墨烯莫尔超晶格来源于六方氮化硼衬底对石墨烯的二维周期势调控.由于这种外加的周期势对石墨烯能带具有显著的调制作用,近年来引发了人们广泛的关注.利用氮化硼衬底上外延的单晶石墨烯薄膜,我们系统研究了基底调制下的莫尔超晶格以及相关的物理特性.首先,我们在电子端和空穴端都观测到了超晶格狄拉克点,并且超晶格狄拉克点同本征狄拉克点类似,都表现出绝缘体的特性.在低温强磁场下,可以观测到到单层石墨烯和双层石墨烯的量子霍尔效应.并且,从朗道扇形图中,可以清晰的看到磁场下形成的超晶格朗道能级.此外,利用红外光谱的方法研究了强磁场下石墨烯超晶格体系不同朗道能级之间的跃迁,发现这种跃迁满足有质量狄拉克费米子的行为,对应38 meV的本征能隙.在此基础上,我们在380 meV位置发现一个同超晶格能量对应的光电导峰.通过利用旋量势中三个不同的势分量对光电导峰进行拟合,发现赝自旋杂化势起主导作用.进一步研究表明赝自旋杂化势强度随载流子浓度的增大显著降低,表明电子-电子相互作用引起的旋量势的重构.
The graphene Moore superlattice is derived from the hexagonal boron nitride substrate for the two-dimensional periodic potential regulation of graphene. Since this added periodic potential has a significant modulation effect on the graphene band, in recent years it has led to widespread Concerned about the use of boron nitride substrate epitaxial single crystal graphene thin film, we systematically studied the substrate modulation of the Moore superlattice and the related physical properties.First, we have observed in the electron end and the hole side of the super Lattice Dirac point, and the superlattice Dirac point is similar to the intrinsic Dirac point, showing the characteristics of the insulator. In low temperature magnetic field, can be observed to monolayer graphene and double quantum graphene quantum In addition, the Langmuir level of superlattices formed by the magnetic field can be clearly seen from the Landau fan diagram.In addition, the infrared spectra of graphene superlattice systems under different magnetic fields We find that this transition satisfies the mass Dirac ferm behavior corresponding to the intrinsic energy gap of 38 meV.On the basis of this, we found a photoelectric with a superlattice energy at 380 meV Lead by using spin Three different potential components of the photoconductive peak fitting and found that the pseudo-spin hybrid potential plays a leading role.Further studies have shown that the pseudo-spin hybrid potential intensity with the carrier concentration increases significantly reduced, indicating that the electron- Reconstruction of the Potentials Potential Caused by Electron Interactions.