论文标题
在高磁场上，在补偿半金属中的低磁场上的热电器大大增强
Large enhancement of thermopower at low magnetic field in compensated semimetals
论文作者
论文摘要
具有低电子密度的导体的热电性能可以通过施加的磁场显着改变。例如，最近的工作表明，带有单个载体袋的Dirac/Weyl半学可以表现出大量的热电器增强，当受到足够大的磁场，系统达到极端量子极限，其中仅占据了单个Landau水平。在这里，我们研究了补偿半法的磁化磁性特性，在费米水平上，电子和孔型载体的口袋共存。我们表明，当补偿几乎完成时，此类系统从较小的磁场开始显示热电图的巨大增强，因此$ω_cτ> 1 $以及与极端量子极限相关的严格条件是不需要的。我们根据有关补偿的Weyl半静脉磷化物的最新测量进行了讨论，其中观察到巨大的磁透明效应。我们还计算了补偿半学的Nernst系数，并表明它表现出最大值，而磁场的增加比单个带情况大得多。在无耗散极限的情况下，在霍尔角度很大的情况下，可以用量子霍尔边缘状态来描述热电响应，我们使用此描述将先前的结果推广到多波段案例。
The thermoelectric properties of conductors with low electron density can be altered significantly by an applied magnetic field. For example, recent work has shown that Dirac/Weyl semimetals with a single pocket of carriers can exhibit a large enhancement of thermopower when subjected to a sufficiently large field that the system reaches the extreme quantum limit, in which only a single Landau level is occupied. Here we study the magnetothermoelectric properties of compensated semimetals, for which pockets of electron- and hole-type carriers coexist at the Fermi level. We show that, when the compensation is nearly complete, such systems exhibit a huge enhancement of thermopower starting at a much smaller magnetic field, such that $ω_cτ> 1$, and the stringent conditions associated with the extreme quantum limit are not necessary. We discuss our results in light of recent measurements on the compensated Weyl semimetal tantalum phosphide, in which an enormous magnetothermoelectric effect was observed. We also calculate the Nernst coefficient of compensated semimetals, and show that it exhibits a maximum value with increasing magnetic field that is much larger than in the single band case. In the dissipationless limit, where the Hall angle is large, the thermoelectric response can be described in terms of quantum Hall edge states, and we use this description to generalize previous results to the multi-band case.
