Lattice model of a three-dimensional topological singlet superconductor with time-reversal symmetry.
Lattice model of a three-dimensional topological singlet superconductor with time-reversal symmetry.
复制标题
具有时间反转对称性的三维拓扑单线态超导体的晶格模型。
DOI：
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发表时间：
2009
影响因子：
8.6
通讯作者：
A. Ludwig
中科院分区：
文献类型：
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作者：
A. Schnyder;S. Ryu;A. Ludwig
我们研究三个空间维度的时间反转不变单线态超导体的拓扑相。在这些系统中，拓扑相的特征在于偶数绕组数nu。在表面，这种量子态的拓扑特性通过无间隙狄拉克费米子表面态的 nu 风味的存在而显现出来，这些表面态对于随机杂质的局域化具有鲁棒性。我们构建了一个晶格紧束缚模型，该模型实现了拓扑非平凡相，其中 nu=+/-2。无序对应于表面狄拉克费米子的（非局域化）随机 SU(2) 规范势，导致幂律状态密度 rho() 约为；{1/7}。体有效场理论被提出为 (3+1) 维 SU(2) Yang-Mills 理论，其 θ 项为 θ=pi。
We study topological phases of time-reversal invariant singlet superconductors in three spatial dimensions. In these systems the topological phases are characterized by an even-numbered winding number nu. At the surface the topological properties of this quantum state manifest themselves through the presence of nu flavors of gapless Dirac fermion surface states, which are robust against localization from random impurities. We construct a lattice tight-binding model that realizes a topologically nontrivial phase, in which nu=+/-2. Disorder corresponds to a (nonlocalizing) random SU(2) gauge potential for the surface Dirac fermions, leading to a power-law density of states rho() approximately ;{1/7}. The bulk effective field theory is proposed to be the (3+1)-dimensional SU(2) Yang-Mills theory with a theta term at theta=pi.