Kriisa A, Samaraweera R L, Heimbeck M S, Everitt H O, Reichl C, Wegscheider W, Mani R G
Georgia State University, Dept. of Physics and Astronomy, Atlanta, 30303, USA.
Army Aviation and Missile RD&E Center, Redstone Arsenal, 35898, USA.
Sci Rep. 2019 Feb 20;9(1):2409. doi: 10.1038/s41598-019-39186-2.
The reflected microwave power from the photo-excited high mobility GaAs/AlGaAs 2D device has been measured over the wide frequency band spanning from 30 to 330 GHz simultaneously along with diagonal magnetoresistance as a function of the magnetic field. Easily distinguishable resonances in the reflected power signal are observed at the same magnetic fields as a reduced amplitude in the Shubnikov-de Haas (SdH) oscillations of the diagonal magnetoresistance. The reflection resonances with concurrent amplitude reduction in SdH oscillations are correlated with cyclotron resonance induced by microwave, mm-wave, and terahertz photoexcitation. The magnetoplasma effect was also investigated. The results suggest a finite frequency zero-magnetic-field intercept, providing an estimate for the plasma frequency. The experimentally measured plasma frequency appears to be somewhat lower than the estimated plasma frequency for these Hall bars. The results, in sum, are consistent with an effective mass ratio of m*/m = 0.067, the standard value, even in these high mobility GaAs/AlGaAs devices, at very large filling factors. Preliminary findings from this article have been published as conference proceedings, see Kriisa, A., et al., J. of Phys. Conf. Ser. 864, 012057 (2017).
在30至330GHz的宽频带上，同时测量了光激发高迁移率GaAs/AlGaAs二维器件的反射微波功率，并将其作为磁场的函数测量了对角磁阻。在与对角磁阻的舒布尼科夫-德哈斯（SdH）振荡幅度减小相同的磁场下，观察到反射功率信号中易于区分的共振。SdH振荡中同时出现幅度减小的反射共振与微波、毫米波和太赫兹光激发引起的回旋共振相关。还研究了磁等离子体效应。结果表明存在有限频率零磁场截距，从而给出了等离子体频率的估计值。对于这些霍尔条形器件，实验测量的等离子体频率似乎略低于估计的等离子体频率。总之，即使在这些高迁移率GaAs/AlGaAs器件中，在非常大的填充因子下，结果也与有效质量比m*/m = 0.067（标准值）一致。本文的初步研究结果已作为会议论文发表，见Kriisa, A.等人，《物理学报：会议系列》864, 012057 (2017)。
