Puel T O, Sacramento P D, Continentino M A
Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150-Urca, Rio de Janeiro-RJ 22290-180, Brazil.
J Phys Condens Matter. 2015 Oct 28;27(42):422002. doi: 10.1088/0953-8984/27/42/422002. Epub 2015 Oct 6.
The importance of models with an exact solution for the study of materials with non-trivial topological properties has been extensively demonstrated. The Kitaev model plays a guiding role in the search for Majorana modes in condensed matter systems. Also, the sp-chain with an anti-symmetric mixing among the s and p bands is a paradigmatic example of a topological insulator with well understood properties. Interestingly, these models share the same universality class for their topological quantum phase transitions. In this work we study a two-band model of spinless fermions with attractive inter-band interactions. We obtain its zero temperature phase diagram, which presents a rich variety of phases including a Weyl superconductor and a topological insulator. The transition from the topological to the trivial superconducting phase has critical exponents different from those of Kitaev's model.
具有精确解的模型对于研究具有非平凡拓扑性质的材料的重要性已得到广泛证明。基塔耶夫模型在凝聚态系统中寻找马约拉纳模式方面发挥着指导作用。此外，在s和p能带之间具有反对称混合的sp链是具有明确理解性质的拓扑绝缘体的一个典型例子。有趣的是，这些模型在其拓扑量子相变方面具有相同的普适类。在这项工作中，我们研究了具有吸引性带间相互作用的无自旋费米子的两能带模型。我们得到了其零温度相图，该相图呈现出丰富多样的相，包括外尔超导体和拓扑绝缘体。从拓扑超导相到平凡超导相的转变具有与基塔耶夫模型不同的临界指数。
