Perturbative Approach to Flat Chern Bands in the Hofstadter Model
Perturbative Approach to Flat Chern Bands in the Hofstadter Model
复制标题
Hofstadter 模型中平陈能带的微扰方法
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
R. Roy
中科院分区：
文献类型：
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作者：
Fenner Harper;S. Simon;R. Roy
每个元格接近于有理分数。在这种近似下，系统的某些本征态被证明是平滑地连接到连续谱的朗道能级的多分量波函数。这些微扰修正是更高的朗道水平的贡献，打破旋转不变性，并允许微扰状态采取的对称性的晶格。在存在相互作用的情况下，这种方法允许计算广义Haldrone赝势，反过来，系统的多体性质。该方法具有很好的通用性，可以应用于各种晶格、相互作用和磁场强度。
per plaquette is close to a rational fraction. Within this approximation, certain eigenstates of the system are shown to be multi-component wavefunctions that connect smoothly to the Landau levels of the continuum. The perturbative corrections to these are higher Landau level contributions that break rotational invariance and allow the perturbed states to adopt the symmetry of the lattice. In the presence of interactions, this approach allows for the calculation of generalised Haldane pseudopotentials, and in turn, the many-body properties of the system. The method is suciently general that it can apply to a wide variety of lattices, interactions, and magnetic eld strengths.