Defect-Site Dependence of Quasiparticle Scattering Channels in the Dirac Semimetal ZrSiS
Yu-Mi Wu1*, Christopher J. Butler1, Cheng-Rong Hsing2, Raman Sankar3,4, Yi Tseng1, Ching-Ming Wei2, Fang-Cheng Chou4,5,6, Minn-Tsong Lin1,2,7
1Department of Physics, National Taiwan University, Taipei, Taiwan
2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
3Institute of Physics, Academia Sinica, Taipei, Taiwan
4Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan
5Taiwan Light Source, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
6Taiwan Consortium of Emergent Crystalline Materials (TCECM), Ministry of Science and Technology, Taipei, Taiwan
7Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
* Presenter:Yu-Mi Wu,
Scanning Tunneling Microscopy (STM) observations of quasiparticle interference (QPI) have become a powerful method investigating the scattering selectivity associated with the k-space band properties. However, previously, point defects of various types have been simply treated as generic scattering centers, without further distinctions. Here, by visualizing QPI in the surface local density of states of the Dirac semimetal ZrSiS in spectro-microscopy measurements, we observe that there is a strong selectivity of quasiparticle scattering channels depending on the lattice site of the impurity scattering center [1]. Combining STM and first-principles calculations of QPI mapping allows for the clear distinction of contributions in scattering of defects at different lattice sites. Our result also implies that the scattering between the states with different orbital character is suppressed in momentum space. This observation provides a detailed insight into the relation between calculated orbital characteristics of the surface band and scattering patterns near different impurity centers.

[1] C. J. Butler et al., Quasiparticle Interference in ZrSiS - Strongly Band-Selective Scattering Depending on Impurity Lattice Site. arXiv:1707.00822 (2017).

This project is financially sponsored by Ministry of Science and Technology (Grants No. MOST 105-2119-M-002-004 and No. MOST 105-2119-M-002-013)

Keywords: scanning tunneling microscopy, density functional theory, quasiparticle interference, defect-dependent scattering, Dirac semimetal