Using ultra-high quality SiGe/Si/SiGe quantum wells at millikelvin temperatures, we experimentally compare the energy-averaged effective mass, m, with that at the Fermi level, m F, and verify that the behaviours of these measured values are qualitatively different. With decreasing electron density (or increasing interaction strength), the 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 behaviour reveals a precursor to the interaction-induced single-particle spectrum flattening at the Fermi level in this electron system.
展开▼
机译：通过在毫微卡尔文温度下使用超高质量SiGe / Si / SiGe量子阱，我们通过实验比较了能量平均有效质量m和费米能级m F的能量平均有效质量，并验证了这些测量值的行为在质上有所不同。随着电子密度的降低（或相互作用强度的提高），费米能级的质量在整个电子密度范围内单调增加，而能量平均质量在低密度下达到饱和。质的不同行为揭示了该电子系统中费米能级相互作用诱导的单粒子光谱变平的先兆。
展开▼
