与电荷和自旋不同，过渡金属氧化物中电子的轨道自由度难以检测。通过分析光谱成像扫描隧道光谱的准粒子散射干涉（QPI）图样，对金属轨道活性体系中的一种新的探测方法进行了理论研究。在$t_{2g}$轨道系统中，$d_{xz}$和$d_{yz}$轨道带的QPI显示出特有的条纹状特征，这是由于它们的准一维性质，这对轨道杂化是稳健的。随着Sr $_3$ Ru $_2$ O $_7$和铁磷属元素化合物中提出的轨道有序的出现，条状的QPI花样表现出破坏$C_4$对称性的扭曲畸变.
英文摘要：
Unlike charge and spin, the orbital degree of freedom of electrons in transition metal oxides is difficult to detect. We present the theoretical study of a new detection method in metallic orbitally active systems by analyzing the quasiparticle scattering interference (QPI) pattern of the spectroscopic imaging scanning tunneling spectroscopy, which is sensitive to orbital structures and orbital ordering. The QPIs for the $d_{xz}$ and $d_{yz}$-orbital bands in the $t_{2g}$-orbital systems show a characteristic stripe-like feature as a consequence of their quasi-one-dimensional nature, which is robust against orbital hybridization. With the occurrence of orbital ordering proposed in Sr$_3$Ru$_2$O$_7$ and iron-pnictides, the stripe-like QPI patterns exhibit nematic distortion breaking the $C_4$-symmetry.
Analyzing scanning tunneling spectroscopy for Fe-based superconductor Ba$_{1-x}$K$_x$Fe$_2$As$_2$ and extracting $s$-wave density of states
我们从Ba $_{1-x}$ K $_x$ Fe $_2$ As $_2$超导体的扫描隧道谱数据中提取了态密度。所得到的样品DOS由两种普通的$s$波型和一种线性DOS组成，前者来自布里渊区的$Γ$点，后者来自布里渊区的M点，并与角分辨光电子能谱的相应数据一致.我们澄清，隧穿电导的主峰是不相关的DOS，而是非平衡相干隧穿，包括所有的相干自旋在尖端和样品的效果。
