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arXiv 1503.04394cond-mat.mes-hallcond-mat.mtrl-sci
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具有短程势的拓扑半金属的高场磁导性

High-field magnetoconductivity of topological semimetals with short-range potential

Hai-Zhou Lu, Song-Bo Zhang, Shun-Qing Shen

摘要:

外尔半金属是物质的三维拓扑状态,在某种意义上,它们在动量空间中拥有成对的Berry曲率的单极子和反单极子,导致手征异常。手征反常在平行强磁场中具有正的磁导性或负的磁电阻率。然而,最近的几个实验外尔和狄拉克拓扑半金属显示在高场负的磁导率。在这里,我们研究的Weyl和狄拉克半金属在短程散射势的存在下的磁导率。在沿两个Weyl节点连接方向施加的强磁场中,我们发现沿磁场方向的电导率由费米速度决定,而不是由朗道简并度决定。我们确定了三种情况下,高场磁导率是负的。我们的研究结果表明,高场正磁导率可能不是一个令人信服的签名的手征异常,并将有助于解释最近的实验和早期的理论的不一致性。

英文摘要:

Weyl semimetals are three-dimensional topological states of matter, in a sense that they host paired monopoles and antimonopoles of Berry curvature in momentum space, leading to the chiral anomaly. The chiral anomaly has long been believed to give a positive magnetoconductivity or negative magnetoresistivity in strong and parallel fields. However, several recent experiments on both Weyl and Dirac topological semimetals show a negative magnetoconductivity in high fields. Here, we study the magnetoconductivity of Weyl and Dirac semimetals in the presence of short-range scattering potentials. In a strong magnetic field applied along the direction that connects two Weyl nodes, we find that the conductivity along the field direction is determined by the Fermi velocity, instead of by the Landau degeneracy. We identify three scenarios in which the high-field magnetoconductivity is negative. Our findings show that the high-field positive magnetoconductivity may not be a compelling signature of the chiral anomaly and will be helpful for interpreting the inconsistency in the recent experiments and earlier theories.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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