School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan.
Nat Commun. 2018 Oct 8;9(1):4153. doi: 10.1038/s41467-018-06661-9.
Non-symmorphic crystals are generating great interest as they are commonly found in quantum materials, like iron-based superconductors, heavy-fermion compounds, and topological semimetals. A new type of surface state, a floating band, was recently discovered in the nodal-line semimetal ZrSiSe, but also exists in many non-symmorphic crystals. Little is known about its physical properties. Here, we employ scanning tunneling microscopy to measure the quasiparticle interference of the floating band state on ZrSiSe (001) surface and discover rotational symmetry breaking interference, healing effect and half-missing-type anomalous Umklapp scattering. Using simulation and theoretical analysis we establish that the phenomena are characteristic properties of a floating band surface state. Moreover, we uncover that the half-missing Umklapp process is derived from the glide mirror symmetry, thus identify a non-symmorphic effect on quasiparticle interferences. Our results may pave a way towards potential new applications of nanoelectronics.
非对称晶体因其在量子材料中普遍存在而引起了极大的兴趣，如铁基超导体、重费米子化合物和拓扑半金属。最近在节线半金属 ZrSiSe 中发现了一种新型的表面态，即浮带，但它也存在于许多非对称晶体中。关于它的物理性质知之甚少。在这里，我们采用扫描隧道显微镜测量了 ZrSiSe(001)表面浮带态的准粒子干涉，并发现了旋转对称性破缺干涉、愈合效应和半缺失型反常 Umklapp 散射。通过模拟和理论分析，我们确定了这些现象是浮带表面态的特征性质。此外，我们揭示了半缺失的 Umklapp 过程来源于滑移镜面对称性，从而确定了准粒子干涉中非对称效应的存在。我们的研究结果可能为纳米电子学的潜在新应用铺平道路。
