论文标题
INAS的巨型Seebeck效果
Giant Seebeck effect across the field-induced metal-insulator transition of InAs
论文作者
论文摘要
轻度掺杂的III-V半导体INAS是一种稀有金属，在应用适度的磁场时，它可以超出其极端量子限制。在这个制度中，由磁场触发的莫特·安德森金属绝缘体跃迁导致载体浓度的耗尽多个数量级。在这里，我们表明这种过渡伴随着Seebeck系数的两百倍增强，该系数的大于11.3mv.k $^{ - 1} \ of 130 \ frac {k_b} {e} {e} {e} $在t = 8k和b = 29t。我们发现，该信号的大小取决于样品维度，并得出结论，它是由声子阻力引起的，这是由于声子的散射时间（几乎是弹道）和电子（几乎位于绝缘状态）之间的巨大差异。我们的结果揭示了在其他低密度系统中的大型热电响应来源区分量子超过量子极限的途径。
Lightly doped III-V semiconductor InAs is a dilute metal, which can be pushed beyond its extreme quantum limit upon the application of a modest magnetic field. In this regime, a Mott-Anderson metal-insulator transition, triggered by the magnetic field, leads to a depletion of carrier concentration by more than one order of magnitude. Here, we show that this transition is accompanied by a two-hundred-fold enhancement of the Seebeck coefficient which becomes as large as 11.3mV.K$^{-1}\approx 130\frac{k_B}{e}$ at T=8K and B=29T. We find that the magnitude of this signal depends on sample dimensions and conclude that it is caused by phonon drag, resulting from a large difference between the scattering time of phonons (which are almost ballistic) and electrons (which are almost localized in the insulating state). Our results reveal a path to distinguish between possible sources of large thermoelectric response in other low density systems pushed beyond the quantum limit.
