发表机构
Ioffe Institute（约费研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对极低温度下电子 - 电子散射弱却存在巨大负磁阻的难题，本文建立二维电子混合磁输运理论，解释了超高品质 GaAs 量子阱的低温磁输运本质。
AI 中文摘要
近十年来，在高质量纳米结构中发现了由快速电子间碰撞诱导的电子输运流体动力学 regime（ regime 译为“ regime” ，此处保留专业术语）。然而，即使在电子 - 电子散射弱到不足以影响输运的极低温度下，仍观察到流体动力学输运的迹象，主要是巨大的负磁阻。为解决这一难题，本文建立了零温度下二维电子在弱但仍重要的无序样品中混合流体动力学与非马尔可夫磁输运的理论，即同时考虑磁场中局域缺陷对电子散射的记忆效应，以及体缺陷和样品粗糙边缘对电子散射产生的非常规粘滞效应。该模型的解给出了强负磁阻，其在零磁场下，较窄样品中呈现尖锐峰值，较宽样品中呈现钝峰值。这一结果及其他结果解释了在超高品质 GaAs 量子阱中观察到的巨大负磁阻的各种特性，从而明确揭示了这些系统中低温磁输运的本质。
英文摘要
The hydrodynamic regime of electron transport, induced by fast inter-electron collisions, was discovered in high-quality nanostructures in recent ten years. However, signs of hydrodynamic transport, primarily, the giant negative magnetoresistance, were observed even at very low temperatures, when electron-electron scattering is too weak to affect the transport. To address this puzzle, here we develop a theory of mixed, hydrodynamic and non-Markovian, magnetotransport of two-dimensional electrons at zero temperature in samples with weak but still important disorder. Namely, we account for both the memory effects at electron scattering by localized defects in magnetic field and an unconventional viscosity effect due to electron scattering by defects in bulk and by rough sample edges. Solution of the model yields a strong negative magnetoresistance, which exhibits at zero magnetic field a sharp maximum in narrower samples or a blunt maximum in wider samples. This and other our results explain various properties of the giant negative magnetoresistance observed on ultra-high-quality GaAs quantum wells, thereby we apparently reveal the nature of low-temperature magnetotransport in these systems.
Comments18 pages, 7 figures
