Code 6393, Naval Research Laboratory, Washington, District of Columbia 20375, USA.
Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 1, 60438 Frankfurt am Main, Germany.
Nat Commun. 2014 Jul 1;5:4261. doi: 10.1038/ncomms5261.
Recently, the most intensely studied objects in the electronic theory of solids have been strongly correlated systems and graphene. However, the fact that the Dirac bands in graphene are made up of sp(2) electrons, which are subject to neither strong Hubbard repulsion U nor strong Hund's rule coupling J, creates certain limitations in terms of novel, interaction-induced physics that could be derived from Dirac points. Here we propose GaCu3(OH)6Cl2 (Ga-substituted herbertsmithite) as a correlated Dirac-Kagome metal combining Dirac electrons, strong interactions and frustrated magnetic interactions. Using density functional theory, we calculate its crystallographic and electronic properties, and observe that it has symmetry-protected Dirac points at the Fermi level. Its many-body physics is diverse, with possible charge, magnetic and superconducting instabilities. Through a combination of various many-body methods we study possible symmetry-lowering phase transitions such as Mott-Hubbard, charge or magnetic ordering, and unconventional superconductivity, which in this compound assumes an f-wave symmetry.
最近，固体电子理论中研究最深入的对象是强关联体系和石墨烯。然而，石墨烯中的狄拉克能带是由 sp(2) 电子组成的，这些电子既不受强 Hubbard 排斥 U 也不受强 Hund 规则耦合 J 的影响，这在可能从狄拉克点导出的新型相互作用诱导物理方面存在一定的局限性。在这里，我们提出 GaCu3(OH)6Cl2（Ga 取代的羟氯铜锌矿）作为一种关联的狄拉克- kagome 金属，结合了狄拉克电子、强相互作用和受挫的磁相互作用。利用密度泛函理论，我们计算了它的晶体和电子性质，并观察到它在费米能级处具有对称保护的狄拉克点。它的多体物理性质多样，可能存在电荷、磁性和超导不稳定性。通过结合各种多体方法，我们研究了可能的对称降低相变，如莫特-洪德、电荷或磁性有序以及非常规超导，在这种化合物中，超导具有 f 波对称性。
