First-Principles Modeling of Electronic Structure and Quasiparticle Scattering Patterns in the Dirac Nodal-Line Semimetal ZrSiS
碩士 === 國立臺灣大學 === 物理學研究所 === 105 === ZrSiS is a Dirac semimetal hosting high mobility, linearly dispersive quasiparticle bands which intersect at a closed loop in momentum space, known as a Dirac-nodal line. In this work, we investigate the electronic properties and the surface morphology of ZrSiS b...
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| Format: | Others |
| Language: | en_US |
| Published: |
2017
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| Online Access: | http://ndltd.ncl.edu.tw/handle/b6xgkp |
| Summary: | 碩士 === 國立臺灣大學 === 物理學研究所 === 105 === ZrSiS is a Dirac semimetal hosting high mobility, linearly dispersive quasiparticle bands which intersect at a closed loop in momentum space, known as a Dirac-nodal line. In this work, we investigate the electronic properties and the surface morphology of ZrSiS by combining density functional theory calculations as well as scanning tunneling microscopy and spectroscopy experiments. By visualizing quasiparticle interference (QPI) in the surface local density of states in spectro-microscopy measurements, we observe that there is a strong selectivity of quasiparticle scattering channels in momentum space, depending on the lattice site of the impurity scattering center. Therefore, the calculated orbital-resolved constant-energy contours and QPI patterns at the surface of ZrSiS are presented and show that simulations of QPI mapping allow for the clear distinction of contributions in scattering of defects at different lattice sites. This 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 center.
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