Condensed-Matter Physics & Materials Science Seminar
"Topological semimetals predicted from first-principles and theoretical approaches"
Presented by Jiawei Ruan, School of Physics, Nanjing University, China
Monday, April 1, 2019, 11:00 am — Building 734, Seminar Room 201
Weyl semimetals are new states of matter which feature novel Fermi arcs and exotic transport phenomena. Based on first-principles calculations, we report that the HgTe-class materials  as well as four chalcopyrites  are ideal Weyl semimetals, having largely separated Weyl points and uncovered Fermi arcs that are amenable to experimental detections. We also construct a minimal effective model to capture the low-energy physics of this class of Weyl semimetals. Our discovery is a major step toward a perfect playground of intriguing Weyl semimetals and potential applications for low-power and high-speed electronics. Besides the ideal Weyl semimetals, I will talk about Non-Hermitian nodal-line semimetals with an anomalous bulk-boundary correspondence . I will also present recent results of saddle surface in topological materials and a new method to construct a simplified tight-binding model based on group theory analysis.  JR et al., Nature communications 7, 11136 (2016).  JR et al., PRL 116, 226801 (2016).  H. Wang, JR, and H. Zhang, PRB 99, 075130 (2019).
Hosted by: Weiguo Yin
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