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Nodal loop Weyl semimetal in the presence of quasiperiodic potentials

作者:点击次数:更新时间:2019年11月14日

报告题目:Nodal loop Weyl semimetal in the presence of quasiperiodic potentials

:   Tilen Cadez (中科院理论物理所)

   间:  20191120号(星期三)上午10:00

   点:  物理学院LE201(理论物理平台)

Abstract

In this seminar I will discuss the bulk phases of a three dimensional nodal loop Weyl semimetal in the presence of a quasiperiodic (QP) potential. Using numerical techniques (exact diagonalization and the Kernel polynomial method), as well as an effective low energy Hamiltonian, we show that the ballistic semimetal phase is robust to weak QP potentials. Upon increasing the potential, the ballistic semimetal transitions into a diffusive metal, which is reflected in the behavior of the density of states, local ratios of adjacent gaps and by the multifractal analysis of the wavefunctions. In this phase, the density of states becomes strongly modulated and develops a peak at zero energy, the low energy levels display a quadratic level repulsion and the ground state wave-function shows a single fractal trend with a fractal dimension 3. By further increasing the potential the system turns into an Anderson insulator.

 

Speaker :

Tilen Cadez obtained his PhD from the University of Ljubljana, Slovenia in 2013. He was a Postdoctoral Fellow at the Beijing Computational Science Research Center (CSRC) between 2014-2019. Currently he is a visiting researcher at the Institute of Theoretical Physics, Chinese Academy of Sciences (ITP CAS). His research interests include: I)topological, II) disordered, III) driven and IV) one-dimensional strongly correlated systems.