Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
Phys Rev Lett. 2013 Jul 19;111(3):037205. doi: 10.1103/PhysRevLett.111.037205.
We study two Kitaev-Heisenberg t-J-like models on a honeycomb lattice, focusing on the zigzag magnetic phase of Na(2)IrO(3), and investigate hole motion by exact diagonalization and variational methods. The spectral functions are quite distinct from those of cuprates and are dominated by large incoherent spectral weight at high energy, almost independent of the microscopic parameters-a universal and generic feature for zigzag magnetic correlations. We explain why quasiparticles at low energy are strongly suppressed in the photoemission spectra and determine an analog of a pseudogap. We point out that the qualitative features of the predominantly incoherent spectra obtained within the two different models for the zigzag phase are similar, and they have a remarkable similarity to recently reported angular resolved photoemission spectra for Na(2)IrO(3).
我们研究了两个在蜂窝晶格上的 Kitaev-Heisenberg t-J 类似模型，重点关注 Na(2)IrO(3)的锯齿磁相，并通过精确对角化和变分方法研究了空穴运动。能带结构与铜酸盐有很大的不同，在高能处主要由大的非相干能带权重主导，几乎与微观参数无关——这是锯齿磁关联的普遍和通用特征。我们解释了为什么在低能区的准粒子在光电子能谱中被强烈抑制，并确定了赝能隙的类似物。我们指出，在两种不同的锯齿相模型中得到的主要是非相干谱的定性特征是相似的，它们与最近报道的 Na(2)IrO(3)的角分辨光电子能谱有显著的相似性。
