Melnikov M Yu, Shashkin A A, Dolgopolov V T, Huang S-H, Liu C W, Kravchenko S V
Institute of Solid State Physics, Chernogolovka, Moscow District, 142432, Russia.
Department of Electrical Engineering and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, 106, Taiwan.
Sci Rep. 2017 Nov 6;7(1):14539. doi: 10.1038/s41598-017-15117-x.
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 , 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.
在毫开尔文温度下使用超高质量的SiGe/Si/SiGe量子阱，我们通过实验比较了能量平均有效质量m与费米能级处的有效质量m*，并验证了这些测量值的行为在定性上是不同的。随着电子密度的降低（或相互作用强度的增加），费米能级处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时达到饱和。这种定性上不同的行为揭示了在这个电子系统中费米能级处相互作用诱导的单粒子谱扁平化的前兆。
