论文标题
在kramers weyl semimetals的量子极限中的负纵向磁阻的理论
Theory for the negative longitudinal magnetoresistance in the quantum limit of Kramers Weyl semimetals
论文作者
论文摘要
在非磁性材料中，负磁势很少。最近，在$β$ -AG $ _2 $ se的量子极限中观察到了一个负磁场，其中只有一个与施加电流平行的强磁场中仅占据了一个兰道级。 $β$ -AG $ _2 $ se是一种材料，可容纳kramers weyl锥，并在费米能源附近带有带堕落的材料。 Kramers Weyl锥存在于所有拟合性手性晶体中的时间反转不变动量，并且在这些动量的子集（包括$γ$点）的子集中，在非符号型手性晶体中。在这里，我们提出了一种在kramers weyl半法的量子极限中的负磁倍率的理论。我们表明，尽管有一条与Weyl Semimetals相似的频带接触，但如果没有手性异常，则可以存在负磁力。我们发现它需要电子和杂质之间筛选的库仑散射电位，这在$β$ -AG $ _2 $ se中自然就是这种情况。
Negative magnetoresistance is rare in non-magnetic materials. Recently, a negative magnetoresistance has been observed in the quantum limit of $β$-Ag$_2$Se, where only one band of Landau levels is occupied in a strong magnetic field parallel to the applied current. $β$-Ag$_2$Se is a material that host a Kramers Weyl cone with band degeneracy near the Fermi energy. Kramers Weyl cones exist at time-reversal invariant momenta in all symmorphic chiral crystals, and at a subset of these momenta, including the $Γ$ point, in non-symmorphic chiral crystals. Here, we present a theory for the negative magnetoresistance in the quantum limit of Kramers Weyl semimetals. We show that, although there is a band touching similar to those in Weyl semimetals, negative magnetoresistance can exist without a chiral anomaly. We find that it requires screened Coulomb scattering potentials between electrons and impurities, which is naturally the case in $β$-Ag$_2$Se.
