Rachel Stephan, Göthel Ilja, Arovas Daniel P, Vojta Matthias
Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany.
Department of Physics, University of California, San Diego, La Jolla, California 92093, USA.
Phys Rev Lett. 2016 Dec 23;117(26):266801. doi: 10.1103/PhysRevLett.117.266801. Epub 2016 Dec 21.
Certain nonuniform strain applied to graphene flakes has been shown to induce pseudo-Landau levels in the single-particle spectrum, which can be rationalized in terms of a pseudomagnetic field for electrons near the Dirac points. However, this Landau level structure is, in general, approximate and restricted to low energies. Here, we introduce a family of strained bipartite tight-binding models in arbitrary spatial dimension d and analytically prove that their entire spectrum consists of perfectly degenerate pseudo-Landau levels. This construction generalizes the case of triaxial strain on graphene's honeycomb lattice to arbitrary d; in d=3, our model corresponds to tetraxial strain on the diamond lattice. We discuss general aspects of pseudo-Landau levels in arbitrary d.
已表明，施加于石墨烯薄片的某些非均匀应变会在单粒子谱中诱导出赝朗道能级，这可以根据狄拉克点附近电子的赝磁场来解释。然而，这种朗道能级结构通常是近似的，并且局限于低能量。在这里，我们引入了一族在任意空间维度(d)下的应变二分紧束缚模型，并通过解析证明其整个谱由完全简并的赝朗道能级组成。这种构造将石墨烯蜂窝晶格上的三轴应变情况推广到了任意(d)；在(d = 3)时，我们的模型对应于金刚石晶格上的四轴应变。我们讨论了任意(d)下赝朗道能级的一般方面。
