论文标题
一种实用方法，用于检测，分析和工程的高级范·霍夫（Van Hove）奇异性
A practical method to detect, analyse and engineer higher order Van Hove singularities in multi-band Hamiltonians
论文作者
论文摘要
我们提出了一种实用方法，用于检测，诊断和工程师高级范·霍夫（Van Hove）的奇异性，对乐队的数量和跳跃术语没有限制。该方法允许我们使用Feynman Hellmann定理的广义扩展，直接计算动量空间中任何频段分散的泰勒扩展，我们陈述并证明。它的范围相当一般，它还使我们能够合并和分析调谐参数对低能分散体的影响，这可以极大地帮助高级范霍夫奇异点的工程。可以在此框架内处理某些堕落的频段。我们通过将其应用于Haldane模型来证明该方法的使用。
We present a practical method to detect, diagnose and engineer higher order Van Hove singularities in multiband systems, with no restrictions on the number of bands and hopping terms. The method allows us to directly compute the Taylor expansion of the dispersion of any band at arbitrary points in momentum space, using a generalised extension of the Feynman Hellmann theorem, which we state and prove. Being fairly general in scope, it also allows us to incorporate and analyse the effect of tuning parameters on the low energy dispersions, which can greatly aid the engineering of higher order Van Hove singularities. A certain class of degenerate bands can be handled within this framework. We demonstrate the use of the method, by applying it to the Haldane model.
