Quantum Hall Resistance Standards With Good Quantization at High Electron Mobilities

We study the magnetotransport properties and Hall resistance quantization in a set of AlGaAs/GaAs heterostructures grown in a high-mobility molecular beam epitaxy system. The data show that, with reduced spacer layer width, the electron mobility in such heterostructures can be reduced to moderate mobility values of ~6 × 10⁵ cm²/(V · s). We And good resistance quantization, allowing for a metrological application not only for a quantum Hall device with moderate electron mobility but also for a high-mobility device with an electron mobility of 2.2 × 10⁶ cm²/(V · s).