面内磁场中的二维输运
2D Transport in an in-plane magnetic field
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中文总结 AI 辅助
研究面内磁场中二维金属 - 绝缘体转变的两种竞争情景，通过自旋极化降低屏蔽来区分维格纳结晶和安德森局域化，给出一般理论及自旋极化对转变密度影响的定量结果，指出主要散射源不同时临界密度的变化情况。
中文摘要 AI 辅助
原则上，平行面内磁场可区分实验观察到的密度调谐二维金属 - 绝缘体转变（载流子密度降低导致从有效金属到有效绝缘体的转变）的两种竞争物理情景：维格纳结晶或安德森局域化。由于二维掺杂半导体中的主要散射机制源于屏蔽随机带电杂质，而屏蔽又取决于电子态密度，面内磁场可通过自旋极化降低屏蔽来区分两者，这使得安德森局域化的有效临界密度相对于维格纳结晶增强。我们给出了一般理论，并通过关注两个近期实验给出了自旋极化对转变密度影响的定量结果，指出如果主要散射是由短程缺陷而非长程带电杂质引起，临界密度实际上可能降低。两种情况的差异源于自旋极化主导屏蔽（增强临界密度）还是费米面（抑制临界密度）。
英文摘要
A parallel in-plane magnetic field could, in principle, distinguish between two competing physical scenarios for the experimentally observed density-tuned 2D metal-insulator transition (where decreasing the carrier density leads to a crossover from an effective metal to an effective insulator): Wigner crystallization or Anderson localization. Since the main scattering mechanism in 2D doped semiconductors arises from screened random charged impurities and screening in turn depends on the electronic density of states, the in-plane magnetic field could distinguish between the two by decreasing screening through spin polarization and this enhances the effective critical density for Anderson localization compared with Wigner crystallization. We give the general theory and provide results for the quantitative magnitudes of the spin polarization effect on the transition density by focusing on two recent experiments [Z. Ge, et al, arXiv:2510.12009, T. Han, et al, arXiv:2604.00113], noting that the critical density may actually decrease if the dominant scattering is by short-ranged defects instead of long-ranged charged impurities. The difference between the two cases arises from whether spin polarization dominates screening (enhanced critical density) or the Fermi surface (suppressed critical density).
