论文标题
伪磁场，粒子孔不对称和微观连续性hamitonians的扭曲双层石墨烯
Pseudo-magnetic fields, particle-hole asymmetry, and microscopic effective continuum Hamitonians of twisted bilayer graphene
论文作者
论文摘要
使用伴侣纸中开发的方法，我们以扭曲的双层石墨烯的两个不同微观的紧密结合模型构建了有效的连续理论，其扭曲角度为$ 1.05^\ circ $，一个基于Slater-koster，另一个基于Ab-Initio Wannier。从连续理论获得的能量光谱（用于刚性扭曲或包括晶格弛豫）几乎完全一致，与从紧密结合模型的光谱进行梯度扩展时，这是完全一致的，这证明了该方法的有效性。我们还分析了所得狭窄带的Bloch状态的性质，发现在我们的连续体理论中，由于连续性理论中的术语，在我们的连续性理论中构建了$γ$点附近的不可忽略的颗粒 - 孔对称性破裂，这是先前被忽略的。这揭示了所有现有的连续模型的差异，在狭窄带希尔伯特空间的粒子孔对称性几乎是完美的。
Using the method developed in the companion paper, we construct the effective continuum theories for two different microscopic tight binding models of the twisted bilayer graphene at the twist angle of $1.05^\circ$, one Slater-Koster based and the other ab-initio Wannier based. The energy spectra obtained from the continuum theory -- either for rigid twist or including lattice relaxation -- are found to be in nearly perfect agreement with the spectra from the tight binding models when the gradient expansion is carried out to second order, demonstrating the validity of the method. We also analyze the properties of the Bloch states of the resulting narrow bands, finding non-negligible particle-hole symmetry breaking near the $Γ$ point in our continuum theory constructed for the ab-initio based microscopic model due to a term in the continuum theory that was previously overlooked. This reveals the difference with all existing continuum models where the particle-hole symmetry of the narrow band Hilbert space is nearly perfect.
