微波诱导电阻振荡(MIRO)的温度依赖性,根据该理论,起源于电子-电子散射。这种散射影响量子寿命或态密度,以及非弹性寿命,这决定了非平衡分布函数的弛豫。在这里,我们报告了在$0.3$ K和$1.8$ K之间的$T$处的迁移率($μ> 3 \times 10^7$ cm $^2$ /Vs)2D电子气中的MIRO。与理论预测相反,量子寿命被发现是$T$ -独立的在整个温度范围内研究。同时,非弹性寿命的$T$依赖性比电子-电子相互作用所能预期的要大\emph{stronger}。
英文摘要:
The temperature dependence of microwave-induced resistance oscillations (MIRO), according to the theory, originates from electron-electron scattering. This scattering affects both the quantum lifetime, or the density of states, and the inelastic lifetime, which governs the relaxation of the nonequilibrium distribution function. Here, we report on MIRO in an ultrahigh mobility ($μ> 3 \times 10^7$ cm$^2$/Vs) 2D electron gas at $T$ between $0.3$ K and $1.8$ K. In contrast to theoretical predictions, the quantum lifetime is found to be $T$-independent in the whole temperature range studied. At the same time, the $T$-dependence of the inelastic lifetime is much \emph{stronger} than can be expected from electron-electron interactions.
利用一种新型的碳掺杂源,在GaAs/AlGaAs异质结中的对称量子阱结构中制备了二维空穴气。在密度为2.3 x 10^11 cm^-2时,GaAs(001)衬底上的低温空穴迁移率高达1.2 x 10^6 cm ^2/Vs。与电子系统相比,空穴迁移率敏感地依赖于量子阱宽度和间隔层厚度的变化。特别地,量子阱宽度从15 nm的最佳值增加到18 nm伴随着空穴迁移率降低35%。超高迁移率电子系统的质量不受所采用的碳掺杂源的影响。
Cascade of fractional quantum Hall states in 2D system
Peking University(北京大学);Max Planck Institute for Solid State Research(马克斯·普朗克固体的研究所);Princeton University(普林斯顿大学);Westlake Institute of Advanced Study(西湖高等研究院);Westlake University(西湖大学);Central South University(中南大学);Huazhong University of Science and Technology(华中科技大学);University of Washington(华盛顿大学);Hefei National Laboratory(合肥国家实验室)