Record-quality GaAs two-dimensional hole systems
نویسندگان
چکیده
The complex band structure, large spin-orbit induced splitting, and heavy effective mass of two-dimensional (2D) hole systems hosted in GaAs quantum wells render them rich platforms to study many-body physics ballistic transport phenomena. Here we report ultra-high-quality (001) 2D systems, fabricated using molecular beam epitaxy modulation doping, with mobility values as high $5.8\times10^6$ cm$^2$/Vs at a density $p=1.3\times10^{11}$ /cm$^2$, implying mean-free path $\simeq27$ $\mu$m. In the low-temperature magnetoresistance trace this sample, observe high-order fractional Hall states up Landau level filling $\nu=12/25$ near $\nu=1/2$. Furthermore, see deep minimum develop $\nu=1/5$ sample much lower $p=4.0\times10^{10}$ /cm$^2$ where measure $3.6\times10^6$ cm$^2$/Vs. These improvements quality were achieved by reduction residual impurities both channel AlGaAs barrier material, well optimization design structure.
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ژورنال
عنوان ژورنال: Physical Review Materials
سال: 2022
ISSN: ['2476-0455', '2475-9953']
DOI: https://doi.org/10.1103/physrevmaterials.6.034005