Revisiting magnetotransport in Weyl semimetals
Revisiting magnetotransport in Weyl semimetals
复制标题
重新审视外尔半金属的磁输运
DOI：
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
S. Tewari
中科院分区：
文献类型：
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作者：
G. Sharma;Sneha Nandy;Karthik Raman;S. Tewari
最近的一系列论文声称，由于外尔半金属（WSM）中的手性异常（CA），仅节点内散射就可以导致正纵向磁导（LMC）。我们重新审视 WSM 中 CA 诱导 LMC 的问题，并表明节点内散射本身不会导致 LMC 增强。在零节间散射的极限下，手性电荷必须保持守恒，这实际上会降低 LMC。仅当存在非零节间散射（无论多么弱）时，由于手性电荷不守恒，才获得正 LMC。即使较弱的节点间散射也足以产生正LMC，因为它在两个节点上重新分配电荷，尽管时间尺度大于节点内散射的时间尺度。此外，我们的计算表明，与最近的工作相比，在非均匀 WSM 中，应变感应轴向磁场 $B_5$ 本身会导致负纵向磁导和负平面霍尔电导。
A series of recent papers have claimed that intranode scattering, alone, can contribute to positive longitudinal magnetoconductance (LMC) due to chiral anomaly (CA) in Weyl semimetals (WSMs). We revisit the problem of CA induced LMC in WSMs, and show that intranode scattering, by itself, does not result in enhancement of LMC. In the limit of zero internode scattering, chiral charge must remain conserved, which is shown to actually decrease LMC. Only in the presence of a non-zero internode scattering (however weak), one obtains a positive LMC due to non-conservation of chiral charge. Even weak internode scattering suffices in generating positive LMC, since it redistributes charges across both the nodes, although on a time scale larger than that of the intranode scattering. Furthermore, our calculations reveal that, in contrast to recent works, in inhomogeneous WSMs strain induced axial magnetic field $B_5$, by itself, leads to negative longitudinal magnetoconductance and a negative planar Hall conductance.