Lee Wei-Cheng, Wu Congjun
Department of Physics, University of California, San Diego, California 92093, USA.
Phys Rev Lett. 2009 Oct 23;103(17):176101. doi: 10.1103/PhysRevLett.103.176101. Epub 2009 Oct 21.
Unlike charge and spin, the orbital degree of freedom of electrons in transition metal oxides is difficult to detect. We present a 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 stripelike feature as a consequence of their quasi-one-dimensional nature, which is robust against orbital hybridization. With the occurrence of orbital ordering proposed in Sr3Ru2O7 and iron pnictides, the stripelike QPI patterns exhibit nematic distortion breaking the C4 symmetry.
与电荷和自旋不同，过渡金属氧化物中电子的轨道自由度很难被检测到。我们通过分析光谱成像扫描隧道谱的准粒子散射干涉（QPI）图案，对金属轨道活性系统中的一种新检测方法进行了理论研究，该图案对轨道结构和轨道序敏感。由于其准一维性质，t(2g)轨道系统中d(xz)和d(yz)轨道带的QPI显示出特征性的条纹状特征，这种特征对轨道杂化具有鲁棒性。随着Sr3Ru2O7和铁基pnictides中提出的轨道序的出现，条纹状QPI图案表现出打破C4对称性的向列畸变。
