论文标题
频段扁平和Landau水平在强相关的二维电子系统中合并
Band Flattening and Landau Level Merging in Strongly-Correlated Two-Dimensional Electron Systems
论文作者
论文摘要
我们回顾了最新的实验结果，表明频带在强相关的二维（2D）电子系统中与化学电位上的兰道水平合并。在SIGE/SIGE/SI/SIGE量子井中的超洁变，强烈相互作用的2D电子系统中，在整个电子密度范围内，费米水平的有效电子质量单调增加，而能量平均值的质量在低密度下饱和。这两个质量的质量不同的行为揭示了该电子系统中相互作用诱导的单粒子光谱在化学势下变平的前体，在这种情况下，在费米水平上的费米昂“凝结”发生在一系列矩范围内，与玻色子的凝结不同。在垂直于2D电子层的强磁场中，在GAAS中观察到SI反转层和BiLayer 2D电子系统，在化学电位上不同量子水平的不同填充物在化学电位上的合并类似。在Ultra-Clean Sige/Si/Sige量子井中还报道了将复合材料费物的量子水平与不同山谷指数合并的指示。
We review recent experimental results indicating the band flattening and Landau level merging at the chemical potential in strongly-correlated two-dimensional (2D) electron systems. In ultra-clean, strongly interacting 2D electron system in SiGe/Si/SiGe quantum wells, the effective electron mass at the Fermi level monotonically increases in the entire range of electron densities, while the energy-averaged mass saturates at low densities. The qualitatively different behavior of the two masses reveals a precursor to the interaction-induced single-particle spectrum flattening at the chemical potential in this electron system, in which case the fermion "condensation" at the Fermi level occurs in a range of momenta, unlike the condensation of bosons. In strong magnetic fields, perpendicular to the 2D electron layer, a similar effect of different fillings of quantum levels at the chemical potential -- the merging of the spin- and valley-split Landau levels at the chemical potential -- is observed in Si inversion layers and bilayer 2D electron system in GaAs. Indication of merging of the quantum levels of composite fermions with different valley indices is also reported in ultra-clean SiGe/Si/SiGe quantum wells.
