Quantum transport in topological semimetals under magnetic fields
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- 作者：Hai-Zhou Lu ; Shun-Qing Shen
- 关键词：topological semimetal ; magnetoconductivity ; magnetoresistance ; localization ; anti ; localization ; chiral anomaly
- 刊名：Frontiers of Physics
- 出版年：2017
- 出版时间：June 2017
- 年：2017
- 卷：12
- 期：3
- 全文大小：1,189 KB
- 刊物类别：Physics and Astronomy
- 刊物主题：Physics
Chinese Library of Science - 出版者：Higher Education Press, co-published with Springer-Verlag GmbH
- ISSN：2095-0470
- 卷排序：12
文摘
Topological semimetals are three-dimensional topological states of matter, in which the conduction and valence bands touch at a finite number of points, i.e., the Weyl nodes. Topological semimetals host paired monopoles and antimonopoles of Berry curvature at the Weyl nodes and topologically protected Fermi arcs at certain surfaces. We review our recent works on quantum transport in topological semimetals, according to the strength of the magnetic field. At weak magnetic fields, there are competitions between the positive magnetoresistivity induced by the weak anti-localization effect and negative magnetoresistivity related to the nontrivial Berry curvature. We propose a fitting formula for the magnetoconductivity of the weak anti-localization. We expect that the weak localization may be induced by inter-valley effects and interaction effect, and occur in double-Weyl semimetals. For the negative magnetoresistance induced by the nontrivial Berry curvature in topological semimetals, we show the dependence of the negative magnetoresistance on the carrier density. At strong magnetic fields, specifically, in the quantum limit, the magnetoconductivity depends on the type and range of the scattering potential of disorder. The high-field positive magnetoconductivity may not be a compelling signature of the chiral anomaly. For long-range Gaussian scattering potential and half filling, the magnetoconductivity can be linear in the quantum limit. A minimal conductivity is found at the Weyl nodes although the density of states vanishes there.