论文标题
最先进的GAAS/藻类量子井中的散射机制
Scattering mechanisms in state-of-the-art GaAs/AlGaAs quantum wells
论文作者
论文摘要
由于最近在GAAS/Algaas量子孔的分子束外延的突破而动机[Y. J. Chung \ textit {等}，自然材料\ textbf {20}，632（2021）]，我们研究了来自各种散射机制及其对电子密度的依赖性的迁移率和量子迁移率的贡献。我们发现，在较低的电子密度下，$ n_e \ sillsim 1 \ times 10^{11} $ cm $ $^{ - 2} $，运输和量子迁移率都受到无意的背景杂质的限制，并遵循power law依赖性，$ \ propto n_e^α$，$ $ lim $ lim $α\ lib 0.85 $。我们对量子迁移率的预测是合理的一致性，即在Y. J. Chung \ textit {et al。}的样本中从电阻率$ν= 1/2 $获得的估计值与$ n_e = 1 \ times 10^{11} $ cm $ $ $ $ $^{ - 2} $。对其他散射机制的考虑表明，界面粗糙度（远程供体）可能是较高电子密度下运输（量子）迁移率的限制因素。量子迁移率的未来测量应产生有关GAA和藻类中背景杂质分布的信息。
Motivated by recent breakthrough in molecular beam epitaxy of GaAs/AlGaAs quantum wells [Y. J. Chung \textit{et al.}, Nature Materials \textbf{20}, 632 (2021)], we examine contributions to mobility and quantum mobility from various scattering mechanisms and their dependencies on the electron density. We find that at lower electron densities, $n_e \lesssim 1 \times 10^{11}$ cm$^{-2}$, both transport and quantum mobility are limited by unintentional background impurities and follow a power law dependence, $\propto n_e^α$, with $α\approx 0.85$. Our predictions for quantum mobility are in reasonable agreement with an estimate obtained from the resistivity at filling factor $ν= 1/2$ in a sample of Y. J. Chung \textit{et al.} with $n_e = 1 \times 10^{11}$ cm$^{-2}$. Consideration of other scattering mechanisms indicates that interface roughness (remote donors) is a likely limiting factor of transport (quantum) mobility at higher electron densities. Future measurements of quantum mobility should yield information on the distribution of background impurities in GaAs and AlGaAs.
