Distinguishing persistent effects in an undoped GaAs/AlGaAs quantum well by top-gate-dependent illumination
Distinguishing persistent effects in an undoped GaAs/AlGaAs quantum well by top-gate-dependent illumination
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DOI：
10.1063/5.0047558
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发表时间：
2021-06
影响因子：
3.2
通讯作者：
T. Fujita;R. Hayashi;M. Kohda;J. Ritzmann;A. Ludwig;J. Nitta;A. Wieck;A. Oiwa
中科院分区：
文献类型：
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作者：
T. Fujita;R. Hayashi;M. Kohda;J. Ritzmann;A. Ludwig;J. Nitta;A. Wieck;A. Oiwa
由于硅掺杂剂相关的深施主能级（DX 中心），GaAs/AlGaAs 异质结构的持续光电导性阻碍了栅极限定量子器件和集成电荷传感器中电荷和自旋相关量子效应的测量。在这项研究中，通过使用用于光子目的的未掺杂的 GaAs/AlGaAs 异质结构来克服这种效应。我们还测量了低温下 LED 照明前后的电子传输。除了显示载流子密度增加的常规快速饱和之外，当在照明期间施加不同的顶栅电压时，还会出现照明效应的缓慢累积，这表明氧化物-GaAs界面处的电荷重新分布。这项研究为高效半导体量子界面的光学稳定器件的开发提供了有趣的见解。
Persistent photoconductivity of GaAs/AlGaAs heterostructures has hampered the measurement of charge- and spin-related quantum effects in gate-defined quantum devices and integrated charge sensors due to Si-dopant-related deep donor levels (DX centers). In this study, this effect is overcome by using an undoped GaAs/AlGaAs heterostructure for photonic purposes. We also measure the electron transport before and after LED illumination at low temperatures. In addition to a regular rapid saturation showing the increased carrier density, a slow accumulation of illumination effects appeared when different top-gate voltages were applied during illumination, which indicated the redistribution of charge at the oxide–GaAs interface. This study provides interesting insights into the development of optically stable devices for efficient semiconductor quantum interfaces.