“Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal)”

Dr. Euyheon Hwang
SAINT and Department of Nanoscience and Technology, Sungkyunkwan University
Jun. 2 (Fri.), 02:30 PM
E6-2. 1st fl. #1323

Abstract:
The effect of quasiparticle interference (QPI) on the spatial variations of the local density of states in topological Weyl semimetal will be presented. We consider the QPI on WTe2 which are known as the type II Weyl semimetals. The Weyl semimetals host topologically protected surface states, with arced Fermi surface contours that are predicted to propagate through the bulk when their momentum matches that of the surface projections of the bulk’s Weyl nodes. Recent progress in spectroscopic techniques has enabled the elucidation of various interesting aspects of the electronic states of Weyl semimetals in real and momentum spaces. A number of characteristic behaviors of interference are identified in the Fourier transformed scanning tunneling spectroscopy. We use the T-matrix approximation to analyze the effect of a localized impurity on the local density of states in WTe2. A comparison between our results and scanning tunneling microscopy experiments could provide a critical test of the electronic properties of WTe2. Our results reveal various different scattering wave vectors, which can be understood by taking into account the shape, spin texture, and momentum-dependent propagation of the Fermi arc surface states into the bulk. Our findings provide evidence that Weyl nodes act as sinks for electron transport on the surface of these materials.