论文标题
围绕绝缘子的电阻率饱和
Resistivity saturation in Kondo insulators
论文作者
论文摘要
重铁绝缘子的电阻率通常在特征温度$ t^*$以下饱和。对于某些人而言，金属表面状态可能来自非平凡的大块拓扑，可能是残留传导的来源。在这里，我们建立了一种替代机制：在低温下，除了电荷差距外，散射速率变成了相关的能量尺度，使半经典的玻尔兹曼图片无效。内在载体的有限寿命限制了传导，施加了交叉$ t^*$的存在，并控制 - 现在与差距相提并论 - 在其下方出现的量子体制。我们展示了具有逼真的多体模拟的机制，并阐明了近托绝缘体CE的饱和度$ _3 $ _3 $ bi $ _4 $ _4 $ pt $ _3 $，对于剩余传导是一种散装特性，在外部压力下演变为外部压力和变化障碍。使用我们为量子制度得出的现象学公式，我们还取消了SMB $ _6 $的不良批量电导率 - 证明我们的机制广泛适用于相关的窄间隙半导体。
Resistivities of heavy-fermion insulators typically saturate below a characteristic temperature $T^*$. For some, metallic surface states, potentially from a non-trivial bulk topology, are a likely source of residual conduction. Here, we establish an alternative mechanism: At low temperature, in addition to the charge gap, the scattering rate turns into a relevant energy scale, invalidating the semiclassical Boltzmann picture. Finite lifetimes of intrinsic carriers limit conduction, impose the existence of a crossover $T^*$, and control - now on par with the gap - the quantum regime emerging below it. We showcase the mechanism with realistic many-body simulations and elucidate how the saturation regime of the Kondo insulator Ce$_3$Bi$_4$Pt$_3$, for which residual conduction is a bulk property, evolves under external pressure and varying disorder. Using a phenomenological formula we derived for the quantum regime, we also unriddle the ill-understood bulk conductivity of SmB$_6$ - demonstrating that our mechanism is widely applicable to correlated narrow-gap semiconductors.
